Kinds of Knowledge

38. Those things, which are common to all, and which are equally in a part and in the whole, cannot be conceived except adequately.

Proof: Let A be something, which is common to all bodies, and which is equally present in the part of any given body and in the whole.

I say A cannot be conceived except adequately.

For the idea thereof in God will necessarily be adequate (2.7. Coroll.), both in so far as God has the idea of the human body, and also in so far as he has the idea of the modifications of the human body, which (2.16, 25, 27) involve in part the nature of the human body and the nature of external bodies.

That is (2.12,13), the idea in God will necessarily be adequate, both in so far as he constitutes the human mind, and in so far as he has the ideas, which are in the human mind.

Therefore the mind (2.11 Coroll.) necessarily perceives A adequately, and has this adequate perception, both in so far as it perceives itself, and in so far as it perceives its own or any external body, nor can A be conceived in any other manner. Q.E.D.

Corollary: It follows that there are certain ideas or notions common to all men.

For (by Lemma 2) all bodies agree in certain respects, which (by the foregoing Prop.) must be adequately or clearly and distinctly perceived by all.

39. That, which is common to and a property of the human body and such other bodies as are wont to affect the human body, and which is present equally in each part of either, or in the whole, will be represented by an adequate idea in the mind.

Proof: If A is:

• a common property of the human body and external bodies
• equally present in the human body and in the said external bodies

Then there will be an adequate idea of A in God (2.7. Coroll.), both in so far as he has:

• the idea of the human body, and
• the ideas of the given external bodies.

The human body is affected by an external body through that, which it has in common therewith, namely, A;

The idea of this modification will involve the property A (2.16), and therefore (2.7. Coroll.) the idea of this modification, in so far as it involves the property A, will be adequate in God, in so far as God is affected by the idea of the human body;

That is (2.13), in so far as he constitutes the nature of the human mind; therefore (2. 11. Coroll.) this idea is also adequate in the human mind. Q.E.D. –>

Corollary: Hence it follows that the mind is fitted to perceive adequately more things, in proportion as its body has more in common with other bodies.

40. Ideas that spring from adequate ideas in the human mind are also adequate themselves.

This means that (2.11. Coroll.) an idea is in the divine intellect which is from God as the essence of the human mind.

Note 1: I have thus set forth the cause of those notions, which:

• are common to all men, and
• form the basis of our reasonings.

But there are other causes of certain notions, which it would be to the purpose to set forth by this method of ours so we can know which notions are useful and which are not.

Furthermore, we should see:

• what notions are common to everyone,
• what notions are only clear and distinct to those unshackled by prejudice.

We should detect the notions which are ill—founded.

We should discern whence the notions called secondary derived their origin.

Consequently, we should discern:

• the axioms on which they are founded, and
• other points of interest connected with these questions.

But I will skip this subject because:

• I have set it aside for another treatise and
• The reader might become weary by excess wordiness.

Nevertheless, I will briefly set down the causes, whence are derived the terms styled transcendental, such as Being, Thing, Something.

These terms are due to the fact that the human body is limited

It can only distinctly form a certain number of images within itself at the same time.

(I explained in the 2.17 note what an image is.)

If this number be exceeded, the images will begin to be confused.

If this number is largely exceeded, all images will become entirely confused one with another.

Thus, (from 2. Prop. 17 Coroll., and 18) the human mind can distinctly imagine as many things simultaneously, as its body can form images simultaneously.

When the images become confused in the body, the mind also imagines all bodies confusedly without any distinction.

It will comprehend them under one attribute of Being, Thing, etc.

The same conclusion can be drawn from the fact that:

• images are not always equally vivid and
• from other analogous causes

We just need to explain one cause

All may be reduced to this: that these terms represent ideas in the highest degree confused.

From similar causes arise ‘general’ notions such as man, horse, dog, etc.

This is because so many images are formed simultaneously in the human mind.

The powers of imagination break down

The mind loses count of small differences between individuals (e.g. colour, size, etc.) and their definite number.

It only distinctly imagines that, in which all the individuals, in so far as the body is affected by them, agree.

For that is the point, in which each of the said individuals chiefly affected the body.

The mind expresses this by the name ‘man’.

The mind predicates this of an infinite number of particular individuals because it cannot imagine the definite number of individuals.

However, we must bear in mind that these general notions are not formed by all men in the same way.

But they vary in each person according to:

• how the body has been most often affected
• how the mind most easily imagines or remembers

For instance, those who admire the stature of man, will by the name of man, understand an animal of erect stature.

Those who have been used to regard some other attribute, will form a different general image of man

For instance, that man is a laughing animal, a two—footed animal without feathers, a rational animal.

Thus, in other cases, everyone will form general images of things according to the habit of his body

This is why so many controversies have arisen among philosophers, who seek to explain things in nature merely by the images formed of them.

Note 2: In many cases, we perceive and form our general notions.

From particular things represented to our intellect fragmentarily, confusedly, and without order through our senses (2.29. Coroll.).

I call such perceptions as ‘knowledge’ from mere experience. [A Baconian phrase. Nov. Org. Aph. 100. [Pollock, p. 126, n.]

(2.) From symbols, e.g., from the fact of having read or heard certain words we remember things and form certain ideas on them, similar to those through which we imagine things (2.18 note). I shall call both these ways of regarding things knowledge of the first kind, opinion, or imagination.

(3.) From the fact that we have notions common to all men, and adequate ideas of the properties of things (2.38 Coroll., 2.39 and Coroll. and 2.40.) I call this reason and knowledge of the second kind. There is a third kind of knowledge called ‘intuition’.

Intuition comes from an adequate idea of the absolute essence of certain attributes of God to the adequate knowledge of the essence of things.

A single example will illustrate all three kinds of knowledge.

Three numbers are given for finding a fourth number, which shall be to the third as the second is to the first.

Traders multiply the second by the third, and divide the product by the first either because:

• they have not forgotten the rule which they received from a master without any proof, or
• they have often made trial of it with simple numbers, or by virtue of the proof of the 19th proposition of the 7th book of Euclid, namely, in virtue of the general property of proportionals.

But this is not needed with very simple numbers.

For instance, 1 x 2 x 3 are given.

Everyone can see that the fourth proportional is 6.

This is much clearer, because we infer the fourth number from an intuitive grasping of the ratio, which the first bears to the second. –>

41. Knowledge of the first kind is the only source of falsehood.

Knowledge of the second and third kinds is necessarily true.

Proof: We have (in the foregoing note) assigned all those ideas, which are inadequate and confused, to the knowledge of the first kind.

Therefore, this kind of knowledge is the only source of falsehood (2.35).

Furthermore, we assigned to the second and third kinds of knowledge those ideas which are adequate.

Therefore, these kinds are necessarily true (2.34). Q.E.D.

42. Knowledge of the second and third kinds teaches us to distinguish the true from the false.

Proof: This proposition is self—evident.

A person who knows how to distinguish between true and false, must have an adequate idea of true and false.

That is (2.40. note 2), he must know the true and the false by the second or third kind of knowledge.