Spinoza's Ethics: II.P27: Adequate Ideas Are Not Based In Scientific Understanding

Spinoza is asserting that an idea can be adequate without understanding the object of the idea. For example, by touching a hot stove, an individual can have an adequate idea of the pain experienced by touching a hot surface. Adequate understanding does not include knowledge of nerves and their operation in transmitting information about temperature. His demonstration here is more generic but more widely applicable. Ideas can be adequate at a level of generalization of the interaction of component parts - of which there are infinite  - without understanding the component parts.

Idea cujuscunque affectionis corporis humani adæquatam ipsius humani corporis cognitionem non involvit.

Translated as,

The idea of whatsoever modification of the human body does not involve an adequate understanding of the human body itself.

DEMONSTRATIO: Quælibet idea cujuscunque affectionis humani corporis eatenus naturam corporis humani involvit quatenus ipsum humanum corpus certo quodam modo affici consideratur (vide propositionem 16 hujus). At quatenus corpus humanum individuum est quod multis aliis modis affici potest, ejus idea etc. Vide demonstrationem propositionis 25 hujus.

Translated as,

Anywhere the idea of whatsoever modification of the human body involves as such the nature of the human body insofar as the human body itself is considered to be affected in some certain way (see IIP16). But insofar as the human body is an individual because it is able to be affected by many other modes, the idea of it etc. See IIP25D.

Spinoza's Ethics: II.P26: Experiences Of Others Generate Inadequate Ideas

Spinoza views that ideas of things are generally inadequate as the ideas are formed by impressions. These ideas of things generally tell more about the mechanisms giving rise to the ideas than the thing itself. As a result, the critical point of learning is to study the modifications or affections of ones own body. For example, when one is offended by someone, it is easy to conclude that someone is offensive. Instead, Spinoza posits that the adequate idea is to understand the nature of one's own body to be offended. From this adequate understanding, one might gain further adequate understandings.

Mens humana nullum corpus externum ut actu existens percipit nisi per ideas affectionum sui corporis.

Translated as,

The human perceives no external body as actually existing unless through the ideas of modifications of its own body.

DEMONSTRATIO: Si a corpore aliquo externo corpus humanum nullo modo affectum est, ergo (per propositionem 7 hujus) nec idea corporis humani hoc est (per propositionem 13 hujus) nec mens humana idea existentiæ illius corporis ullo etiam modo affecta est sive existentiam illius corporis externi ullo modo percipit. At quatenus corpus humanum a corpore aliquo externo aliquo modo afficitur eatenus (per propositionem 16 hujus cum corollario I ejusdem) corpus externum percipit. Q.E.D.

Translated as,

If by another external body the human body is affected in no way, thus (by IIP7) and not the idea of a human body, that is (by IIP13) and the human mind is not affected by the idea of the existence of that body in another way or it perceived the existence of that external body in any way. But insofar as the human body is affected by another external body in some other way in that far (by IIP16 with IIP16C) does it perceive the external body.

COROLLARIUM: Quatenus mens humana corpus externum imaginatur eatenus adæquatam ejus cognitionem non habet.

Translated as,

Insofar as the human mind imagine the external body so far does it not have an adequate understanding of it.

DEMONSTRATIO: Cum mens humana per ideas affectionum sui corporis corpora externa contemplatur, eandem tum imaginari dicimus (vide scholium propositionis 17 hujus) nec mens alia ratione (per propositionem præcedentem) corpora externa ut actu existentia imaginari potest. Atque adeo (per propositionem 25 hujus) quatenus mens corpora externa imaginatur, eorum adæquatam cognitionem non habet. Q.E.D.

Translated as,

When the human mind contemplates external bodies by ideas of the modifications of its own body, then we say the same then imagines (see IIP17S) and that the mind is not able to imagine by other method (see IIP25) the external bodies as actually existing. And to this extent (by IIP25) insofar as the mind imagines external bodies, it does not have an adequate understanding of them.

Spinoza's Ethics: II.P25: Our Limit to Understanding What Affects Us

Spinoza develops a proposition here that elucidates just how little we have an adequate understanding of that which affects us. His proof involves a causality - because something existed in nature prior to affecting us, this nature is understood in God in a way that is unrelated or as Spinoza puts it, uninvolved with our understanding. In a practical sense, when something affects us, the full understanding of the affect of that thing must be understood from its nature not from the impact we experience and thus impute. This framework is useful in reducing our tendency to personalize experiences and others.

Idea cujuscunque affectionis corporis humani adæquatam corporis externi cognitionem non involvit.

Translated as,

The idea of whatever modification of the human body does not involve the adequate understanding of the external body.

DEMONSTRATIO: Ideam affectionis corporis humani eatenus corporis externi naturam involvere ostendimus (vide propositionem 16 hujus) quatenus externum ipsum humanum corpus certo quodam modo determinat. At quatenus externum corpus individuum est quod ad corpus humanum non refertur, ejus idea sive cognitio in Deo est (per propositionem 9 hujus) quatenus Deus affectus consideratur alterius rei idea quæ (per propositionem 7 hujus) ipso corpore externo prior est natura. Quare corporis externi adæquata cognitio in Deo non est quatenus ideam affectionis humani corporis habet sive idea affectionis corporis humani adæquatam corporis externi cognitionem non involvit. Q.E.D.

Translated as,

We have shown (See IIP16) that the idea of the modification of the human body insofar as it involves the nature of an external body to such an extent the external body certainly determines the human body itself in a certain way. But insofar as the external body is an individual which does not refer to the human body whose idea or understanding is in God (by IIP9) insofar as God is considered an affect of another thing, the idea which (by IIP7) is prior to the external body itself in nature. Thus, the adequate understanding of the external body is not in God insofar as it has the idea of the modification or the human body or the idea of the change of the human body does not involve the adequate understanding of the external body.

Spinoza's Ethics: II.P24: Affects Not Parts Constitute the Human Mind

Spinoza further describes that the human mind does not understand the parts which make up the human body. In his demonstration, he shows that it is not the parts which constitute the human mind, but instead, the relationships of the parts - and particularly when those relationships are changing. It is in this movement which alters a relationship that drive an affect. These affects are the experience of the expressiveness of God within the human body. This identification of expressiveness through the affects is the nature of the human mind and the basis for adequate understanding.

Mens humana partium corpus humanum componentium adæquatam cognitionem non involvit.

Translated as,

The human mind does not involve an adequate understanding of the parts composing the human body.

DEMONSTRATIO: Partes corpus humanum componentes ad essentiam ipsius corporis non pertinent nisi quatenus motus suos certa quadam ratione invicem communicant (vide definitionem post corollarium lemmatis 3) et non quatenus ut individua absque relatione ad humanum corpus considerari possunt. Sunt enim partes humani corporis (per postulatum 1) valde composita individua quorum partes (per lemma 4) a corpore humano, servata omnino ejusdem natura et forma, segregari possunt motusque suos (vide axioma 1 post lemma 3) aliis corporibus alia ratione communicare adeoque (per propositionem 3 hujus) cujuscunque partis idea sive cognitio in Deo erit et quidem (per propositionem 9 hujus) quatenus affectus consideratur alia idea rei singularis, quæ res singularis ipsa parte ordine naturæ prior est (per propositionem 7 hujus). Quod idem præterea etiam de quacunque parte ipsius individui corpus humanum componentis est dicendum adeoque cujuscunque partis corpus humanum componentis cognitio in Deo est quatenus plurimis rerum ideis affectus est et non quatenus corporis humani tantum habet ideam hoc est (per propositionem 13 hujus) ideam quæ humanæ mentis naturam constituit atque adeo (per corollarium propositionis 11 hujus) humana mens partium corpus humanum componentium adæquatam cognitionem non involvit. Q.E.D.

Translated as,

The parts composing the human body do not pertain to the essence of the body itself unless insofar as they communicate their motions by some specific way interactively (see definition after the corollary of lemma 3) and not insofar as they are able to be considered as individual parts from relation to the human body. For they are parts of the human body (by postulate 1) firmly composed individuals whose parts (by lemma 4) from the human body, altogether saving the nature and form of the same, are able to segregate and communicate their motions (see axiom 1 after lemma 3) to other bodies by another way to such a degree (by IIP3) will be the idea of whatsoever part or understanding in God and indeed (by IIP9) insofar as an affect is considered by another idea of a singular thing, which is a singular thing prior by the part itself in the order of nature (by IIP7). Which the same meanwhile even concerning whatsoever part of the individual itself composing the human body must be said to the extent that the understanding of whatsoever part composing the human body is in God insofar as it is the affect by more ideas of things and not insofar as it has only the idea of the human body, that is (by IIP13) the idea which constitutes the nature of human mind and to the extent (by IIP11C) the human mind does not involve the adequate understanding of the parts composing the human body.

Spinoza's Ethics: II.P23: Ideas Rooted In The Body

Spinoza is carefully outlining the limitations of the human mind and its larger role. His primary insight is to highlight the mind's natural tendency to preeminence over the body - both in terms of knowing the body and God. Instead, he has established that the mind is rooted in the body and does not know except insofar as its role in the body as perceiving the modifications of the body. Recognizing our tendency to imagine greater roles, he highlights this limitation and identifies its accuracy as in God or not. Basically, he addresses the argument that our mind should thoroughly understand the functioning of the body. However, such a degree of knowledge of the body does not constitute the nature of the human mind, i.e., many minds function perfectly without such understanding. Where minds require ideas in order to function properly, Spinoza characterizes as "in God."

Mens se ipsam non cognoscit nisi quatenus corporis affectionum ideas percipit.

Translated as,

The mind does not understand itself unless insofar as it perceives the ideas of the modifications of the body.

DEMONSTRATIO: Mentis idea sive cognitio (per propositionem 20 hujus) in Deo eodem modo sequitur et ad Deum eodem modo refertur ac corporis idea sive cognitio. At quoniam (per propositionem 19 hujus) mens humana ipsum humanum corpus non cognoscit hoc est (per corollarium propositionis 11 hujus) quoniam cognitio corporis humani ad Deum non refertur quatenus humanæ mentis naturam constituit; ergo nec cognitio mentis ad Deum refertur quatenus essentiam mentis humanæ constituit atque adeo (per idem corollarium propositionis 11 hujus) mens humana eatenus se ipsam non cognoscit. Deinde affectionum quibus corpus afficitur ideæ naturam ipsius corporis humani involvunt (per propositionem 16 hujus) hoc est (per propositionem 13 hujus) cum natura mentis conveniunt; quare harum idearum cognitio cognitionem mentis necessario involvet; at (per propositionem præcedentem) harum idearum cognitio in ipsa humana mente est; ergo mens humana eatenus tantum se ipsam novit. Q.E.D.

Translated as,

The idea of the mind or its understanding (by IIP20) follows in God in the same way and refers to God in the same way as the idea of the body or its understanding. But since (by IIP19) the human mind does not understand the human body itself, that is (by IIP11C) since the understanding of the human body does not refer to God insofar as it constitutes the nature of the human mind; and thus the understanding of the mind does not refer to God insofar as it constitutes the essence of the human mind and to such a degree (by the same IIP11C) the human mind does not understand itself so long. Next the ideas of the modifications by which the body is affected involve the nature of the human body itself (by IIP16), that is (by IIP13) they coincide with the nature of the mind; thus the understanding of these ideas involves the understanding of the mind necessarily; but (by IIP22) the understanding of these ideas is in the human mind itself; thus the human mind knows itself only to that extent.

Spinoza's Ethics: II. P22: Ideas of Ideas

Spinoza explores the role of the mind as the idea of the body by a methodical analysis. Here he builds on the propositions established earlier which address the mind's capacity to perceive the modifications of the body. As I shared earlier, we often delineate feelings from thoughts. Spinoza does not. The mind's capacity to perceive modifications of the body we call feelings. Feelings are in God in that they are directly experienced when there is a modification of the body and these feelings are ideas. Further, ideas of these ideas are in God in the same way insofar as they constitute the essence of the mind. The distinction here is that a perception of a directly experienced feeling is in God while a perception about a directly experienced feeling is not in God.

Mens humana non tantum corporis affectiones sed etiam harum affectionum ideas percipit.

Translated as,

The human mind not only perceives modifications of the body but also ideas of these modifications.

DEMONSTRATIO: Affectionum idearum ideæ in Deo eodem modo sequuntur et ad Deum eodem modo referuntur ac ipsæ affectionum ideæ; quod eodem modo demonstratur ac propositio 20 hujus. At ideæ affectionum corporis in mente humana sunt (per propositionem 12 hujus) hoc est (per corollarium propositionis 11 hujus) in Deo quatenus humanæ mentis essentiam constituit; ergo harum idearum ideæ in Deo erunt quatenus humanæ mentis cognitionem sive ideam habet hoc est (per propositionem 21 hujus) in ipsa mente humana quæ propterea non tantum corporis affectiones sed earum etiam ideas percipit. Q.E.D.

Translated as,

The ideas of the ideas of modifications follow in God in the same way and refer to God in the same way as the ideas of modifications themselves; which is shown in the same way as IIP20. But ideas of the modifications of the body are in the human mind (by IIP12), that is (by IIP11C) in God insofar as it constitutes the essence of the human mind; therefore the ideas of these ideas are in God insofar as it has the understanding or idea of the human mind, that is (by IIP21) in the human mind itself which perceives in the meantime not only the modifications of the body but also the ideas of these [modifications]. QED