Man can, indeed, act contrarily to the decrees of God, as far as they have been written like laws in the minds of ourselves or the prophets, but against that eternal decree of God, which is written in universal nature, and has regard to the course of nature as a whole, he can do nothing.

Speaking generally, he holds dominion, to whom are entrusted by common consent affairs of state — such as the laying down, interpretation, and abrogation of laws, the fortification of cities, deciding on war and peace, &c. But if this charge belong to a council, composed of the general multitude, then the dominion is called a democracy; if the council be composed of certain chosen persons, then it is an aristocracy ; and, if, lastly, the care of affairs of state, and, consequently, the dominion rest with one man, then it has the name of monarchy.

I have resolved to demonstrate by a certain and undoubted course of argument, or to deduce from the very condition of human nature, not what is new and unheard of, but only such things as agree best with practice.

By Natura naturans we must understand what is in itself and is conceived through itself, or such attributes of substance as express an eternal and infinite essence, that is … God, insofar as he is considered as a free cause. But by Natura naturata I understand whatever follows from the necessity of God's nature, or from God's attributes, that is, all the modes of God's attributes insofar as they are considered as things which are in God, and can neither be nor be conceived without God.

The perfection of a thing does not annul its existence, but, on the contrary, asserts it. Imperfection, on the other hand, does annul it ; therefore we cannot be more certain of the existence of anything, than of the existence of a being absolutely infinite or perfect—that is, of God. For inasmuch as his essence excludes all imperfection, and involves absolute perfection, all cause for doubt concerning his existence is done away, and the utmost certainty on the question is given. This, I think, will be evident to every moderately attentive reader.

A definition, if it is to be called perfect, must explain the inmost essence of a thing, and must take care not to substitute for this any of its properties. In order to illustrate my meaning, without taking an example which would seem to show a desire to expose other people's errors, I will choose the case of something abstract, the definition of which is of little moment. Such is a circle. If a circle be defined as a figure, such that all straight lines drawn from the center to the circumference are equal, every one can see that such a definition does not in the least explain the essence of a circle, but solely one of its properties. Though, as I have said, this is of no importance in the case of figures and other abstractions, it is of great importance in the case of physical beings and realities, for the properties of things are not understood so long as their essences are unknown. If the latter be passed over, there is necessarily a perversion of the succession of ideas which should reflect the succession of nature, and we go far astray from our object.

The ordinary surroundings of life which are esteemed by men (as their actions testify) to be the highest good, may be classed under the three heads — Riches, Fame, and the Pleasures of Sense: with these three the mind is so absorbed that it has little power to reflect on any different good.

After experience had taught me that all the usual surroundings of social life are vain and futile; seeing that none of the objects of my fears contained in themselves anything either good or bad, except in so far as the mind is affected by them, I finally resolved to inquire whether there might be some real good having power to communicate itself, which would affect the mind singly, to the exclusion of all else: whether, in fact, there might be anything of which the discovery and attainment would enable me to enjoy continuous, supreme, and unending happiness.

All the better; they do not force me to do anything that I would not have done of my own accord if I did not dread scandal. But since they want it that way, I enter gladly on the path that is opened to me, with the consolation that my departure will be more innocent than was the exodus of the early Hebrews from Egypt.

Of all the things that are beyond my power, I value nothing more highly than to be allowed the honor of entering into bonds of friendship with people who sincerely love truth. For, of things beyond our power, I believe there is nothing in the world which we can love with tranquility except such men.