The order of those things to which the mind should be directed

The entire method consists in the order and arrangement of those things to which the focus of the mind should be directed, so that we may discover some truth.

We will strictly observe this if we gradually reduce involved and obscure propositions to simpler ones, and then attempt to ascend from the intuition of all the most simple things to the knowledge of all others through the same steps.

In this one rule the entire sum of human industry is contained, and this rule must be observed no less by one who is about to undertake the knowledge of things, than by one who is about to enter the labyrinth of Theseus.

But many either do not reflect on what it prescribes, or are plainly ignorant, or presume that they do not need it, and often examine the most difficult questions in such a disorderly manner that they seem to me to be doing the same as if they attempted to reach the top of a building in one leap from its lowest part, neglecting the steps of the ladder which are destined for this use, or not noticing them.

Thus do all astrologers, who hope they can designate their effects not from a known nature of the heavens, but not even from perfectly observed motions. Thus too many, who study mechanics without physics, and fabricate new instruments for producing motions, without reason. Thus also those philosophers who, neglecting experiments, think truth will arise from their own brain, as Minerva from Jupiter.

Indeed, all these clearly violate this rule. But because the order desired here is often so obscure and intricate that not all can recognize it, they can scarcely take care not to go astray unless they carefully observe what will be set forth in the following proposition.