First part https://steemit.com/science/@uneducated/into-mind-of-rene-descartes-part1

Tips of how to be clever, or "Rules for the Direction of the Mind" from Rene Descartes

THERE IS FULL 21 RULE, I give only main thought
https://en.wikisource.org/wiki/Rules_for_the_Direction_of_the_Mind
Some thought from Professor of Logic
In the University of Oxford
https://archive.org/details/descartessrulesf032479mbp

RULE 1 : The ultimate aim of

study should be to guide the mind so that it can pass
solid and true judgements on all that comes before it.

Art	Science
involves the acquisition of some special bodily skill	The power of knowing is a purely spiritual power, single, self-identical and absolute
so no one person can be master of all the arts(concetraite on something one) - if you good at running you can't be good at powerlifting.	The knowledge of a science increases the power to learn others(spread your mind on different areas) - biology, physics, math

Don't confuse Knowledge with memory

remember is not the same thing as to know; not even the memory of demonstrations.
We might remember all Euclid without knowing it :

knowledge is spiritual insight

into the matters which may be marshalled by memory.

      the power of knowing is neither more nor less than

This idea, I think, came to him from MATH. It looks as equasion.

seeing simple data(intuitus) reveals the first link in the chain,

and provided advance from

link to link by correct logical moving from simple to simple (illation),

never breaking the continuity,
then every element of every part of reality,
as well as the whole, will, in due course be reached.

careful logical analysis will enable us to find the links in any sphere of inquiry, so long as we adopt the proper logical order.

Hence it were better not to study at all than to occupy one's self with objects of such difficulty, that, owing to our inability to distinguish true from false, we are forced to regard the doubtful as certain;

it is much easier to have some vague notion about any subject, no matter what, than to arrive at the real truth about a single question however simple that may be.

RULE 3

Concerning objects proposed for study, we ought to investigate what we can clearly and evidently intuit or deduce with certainty, and not what other people have thought or what we ourselves conjecture. For knowledge can be attained in no other way.

Concerning objects proposed for study, we ought to investigate what we can clearly and evidently intuit or deduce with certainty, and not what other people have thought or what we ourselves conjecture. For knowledge can be attained in no other way.

we shall never be philosophers, if we have read all the arguments of Plato and Aristotle but cannot form a solid judgment on matters set before us;

We had to do this because many things are known although not self-evident, so long as they are deduced from principles known to be true by a continuous and uninterrupted movement of thought, with clear intuition of each point.

Rule V + Rule VI + Rule VII = use as one

numeration is required in order to complete our knowledge.

He said that we should study MATH.

It gives us tools to make models, it's simple and from models we can think about real use.

RULE 9

We must concentrate our mind's eye totally upon the most insignificant and easiest of matters, and dwell on them long enough to acquire the habit of intuiting the truth distinctly and clearly

RULE 10

In order to acquire discernment we should exercise our intelligence by investigating what others have already discovered, and methodically survey even the most insignificant products of human skill, especially those which display or presuppose order.

RULE 13

If we perfectly understand a problem we must abstract it from every superfluous conception, reduce it to its simplest terms and, by means of an enumeration, divide it up into the smallest possible parts.

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