The whole object of the Prophets and the Sages was to declare that a limit is set to human reason where it must halt.

How individuals of the same species surpass each other in these sensations and in other bodily faculties is universally known, but there is a limit to them, and their power cannot extend to every distance or to every degree.

The more necessary a thing is for living beings, the more easily it is found and the cheaper it is; the less necessary it is, the rarer and dearer it is.

There is no difference between the pain of humans and the pain of other living beings, since the love and tenderness of the mother for the young are not produced by reasoning, but by feeling, and this faculty exists not only in humans but in most living beings.

All this is applicable to the intellectual faculties of man. There is a considerable difference between one person and another as regards these faculties, as is well known to philosophers.

It is thus necessary to examine all things according to their essence, to infer from every species such true and well established propositions as may assist us in the solution of metaphysical problems.

To the totality of purposes of the perfect Law there belong the abandonment, depreciation, and restraint of desires in so far as possible.