We assume a common sense as the necessary condition of the universal communicability of our knowledge, which is presupposed in every logic and every principle of knowledge that is not one of skepticism.
Those afraid of the universe as it really is, those who pretend to nonexistent knowledge and envision a Cosmos centered on human beings will prefer the fleeting comforts of superstition. They avoid rather than confront the world. But those with the courage to explore the weave and structure of the Cosmos, even where it differs profoundly from their wishes and prejudices, will penetrate its deepest mysteries.
It is rightly laid down that 'true knowledge is knowledge by causes'. Also the establishment of four causes is not bad: material, formal, efficient and final.
By all means sometimes be alone; salute thyself; see what thy soul doth wear; dare to look in thy chest; and tumble up and down what thou findest there.
The partitions of knowledge are not like several lines that meet in one angle, and so touch not in a point; but are like branches of a tree, that meet in a stem, which hath a dimension and quantity of entireness and continuance, before it come to discontinue and break itself into arms and boughs.
We have no organ at all for knowledge, for truth: we know (or believe or imagine) precisely as much as may be useful in the interest of the human herd, the species: and even what is here called usefulness is in the end only a belief, something imagined and perhaps precisely that most fatal piece of stupidity by which we shall one day perish.
Thoughts without content are empty, intuitions without concepts are blind... The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise.