Axioms or Common Notions.

I. Nothing exists of which it cannot be inquired what is the cause of its existing; for this can even be asked respecting God; not that there is need of any cause in order to his existence, but because the very immensity of his nature is the cause or reason why there is no need of any cause of his existence.

II. The present time is not dependent on that which immediately preceded it; for this reason, there is not need of a less cause for conserving a thing than for at first producing it.

III. Any thing or any perfection of a thing actually existent cannot have nothing, or a thing non-existent, for the cause of its existence.

IV. All the reality or perfection which is in a thing is found formally or eminently in its first and total cause.

V. Whence it follows likewise, that the objective reality of our ideas requires a cause in which this same reality is contained, not simply objectively, but formally or eminently. And it is to be observed that this axiom must of necessity be admitted, as upon it alone depends the knowledge of all things, whether sensible or insensible. For whence do we know, for example, that the sky exists? Is it because we see it? But this vision does not affect the mind unless in so far as it is an idea, and an idea inhering in the mind itself, and not an image depicted on the phantasy; and, by reason of this idea, we cannot judge that the sky exists unless we suppose that every idea must have a cause of its objective reality which is really existent; and this cause we judge to be the sky itself, and so in the other instances.

VI. There are diverse degrees of reality, that is, of entity [or perfection]: for substance has more reality than accident or mode, and infinite substance than finite; it is for this reason also that there is more objective reality in the idea of substance than in that of accident, and in the idea of infinite than in the idea of finite substance.

VII. The will of a thinking being is carried voluntarily and freely, for that is of the essence of will, but nevertheless infallibly, to the good that is clearly known to it; and, therefore, if it discover any perfections which it does not possess, it will instantly confer them on itself if they are in its power; [for it will perceive that to possess them is a greater good than to want them].

VIII. That which can accomplish the greater or more difficult, can also accomplish the less or the more easy.

IX. It is a greater and more difficult thing to create or conserve a substance than to create or conserve its attributes or properties; but this creation of a thing is not greater or more difficult than its conservation, as has been already said.

X. In the idea or concept of a thing existence is contained, because we are unable to conceive anything unless under the form of a thing which exists; but with this difference that, in the concept of a limited thing, possible or contingent existence is alone contained, and in the concept of a being sovereignly perfect, perfect and necessary existence is comprised.