Sources of beliefs

I present here a division of types of beliefs, according to their source, which I made up the other day. Some of them are compounds of other types, which I noted in square brackets.

(a) self-evident knowledge

Such are the laws of logic, such as the law of non-contradiction and the excluded middle. They are the source of the two first divisions.

Also self-evident is the fact that apparent things are knowable, which itself requires that they have the four causes.

(b) pure appearance

A second source of our beliefs is pure appearance, in which I include all of our sense perception, imagination, and memory.

(c) [a+b] knowledge of forms

Since apparent things are knowable, we must have knowledge of their immutable forms.

Besides the self-evident knowledge of the two first divisions, forms are the only objects of knowledge, properly speaking. Our experiences and memories are only known in a weaker sense.

(d) [c, imperfectly] probable inductive judgments

Sometimes, we cannot observe something well enough to understand it. But since the fact that apparent things are knowable requires that all of them have final causes, which is to say, operate according to necessary laws, inductions may be made – we can expect that often, similar appearances will follow each other in similar patterns. So, we can make judgments that they will follow each other in this way in a particular case, which is another source of our beliefs.

Such judgments are probable – they are not knowledge, properly speaking, but may nevertheless be highly certain.

(e) [d+b, or d+c] human faith

Our trust in reports and authority of other human persons is a compound of two probable judgments:

• first, a probable judgment (d) that the person is not mistaken about having knowledge (c), or experience (b), of what he says;

• second, a probable judgment (d) that the person is not lying about having knowledge (c), or experience (b), of what he says.

(f) [c+c] divine faith, in principle

In principle, our faith in God is produced similarly to human faith, but with the caveat that the two probable judgments are replaced with certain knowledge, since it is impossible that God could be lying or mistaken.

So, in principle, beliefs formed through divine faith are just as certain as knowledge of forms (c).

(g) [e+f, or b+f] divine faith, in practice

In practice, our beliefs of divine faith are not formed purely through faith in God, but through experiences (b) that we judge to be of divine origin, or through human reports (e) of such experiences. They are, therefore, as certain as those.

Of course, this is not to say they are terribly uncertain, if the reports come from trustworthy human persons, and the experiences were had in proper conditions.

(h) [d or c, mistaken for c] error, or conceit

If we mistake our probable inductive judgments (d) about something for true knowledge of its nature; or if we have true knowledge of a nature (c) but wrongly judge that a given apparent thing is of that nature, we are in error. Our belief, in such a case, may be called a conceit; Augustine called it opinion, but that word seems liable to mislead.