One should see the world, and see himself as a scale with an equal balance of good and evil. When he does one good deed the scale is tipped to the good - he and the world is saved. When he does one evil deed the scale is tipped to the bad - he and the world is destroyed.
Teach thy tongue to say 'I do not know,' and thou shalt progress.
The same is the case with those opinions of man to which he has been accustomed from his youth; he likes them, defends them, and shuns the opposite views.
To the totality of purposes of the perfect Law there belong the abandonment, depreciation, and restraint of desires in so far as possible.
While one man can discover a certain thing by himself, another is never able to understand it, even if taught by means of all possible expressions and metaphors, and during a long period; his mind can in no way grasp it, his capacity is insufficient for it.
If a person studies too much and exhausts his reflective powers, he will be confused, and will not be able to apprehend even that which had been within the power of his apprehension. For the powers of the body are all alike in this respect.
You must accept the truth from whatever source it comes.
You will certainly not doubt the necessity of studying astronomy and physics, if you are desirous of comprehending the relation between the world and Providence as it is in reality, and not according to imagination.
You must consider, when reading this treatise, that mental perception, because connected with matter, is subject to conditions similar to those to which physical perception is subject.