John Locke quotes - page 6
Encourage therefore his inquisitiveness all you can, by satisfying his demands, and informing his judgement, as far as it is capable. When his reasons are any way tolerable, let him find the credit and commendation of it, without being laugh'd at for his mistake be gently put into the right; and if he shew a forwardness to be reasoning about things that come in his way, take care, as much as you can, that no body check this inclination in him, or mislead it by captious or fallacious ways of talking with him. For when all is done, this is the highest and most important faculty of our minds, deserves the greatest care and attention in cultivating it: the right improvement, and exercise of our reason being the highest perfection that a man can attain to in his life.
John Locke
Much less are children capable of reasonings from remote principles. They cannot conceive the force of long deductions. The reasons that move them must be obvious, and level to their thoughts, and such as may be felt and touched. But yet, if their age, temper, and inclination be consider'd, they will never want such motives as may be sufficient to convince them.
John Locke