'Uncle Martin' wrote:
a. Feelings -1
b. Perceptions -1
c. Concepts 1
d. Beliefs 1
e. Fantasy 2
f. Imagination 2
g. Observation 2
h. Language 2
i. Speculation 3
j. Quantification 3
k. Calculation 4
l . Definitions 7
m. Logic 10
n. Axioms 14
o. Theorems 14
The numbers on the right of the list is my rough guess as to the age of the individual when that typically occurs. (But let's not argue about it; if you don't like my numbers, replace them with your own numbers.)

(snip)
In science, the ideas a - g are shunned while h - o are accepted. In mathematics, while idea k is a by-product, only l - o are accepted in the formal development

"If a writer can group his ideas, then he is a good writer." -- Robert Louis Stevenson

Exceptions have their place.
e. Einstein recommended reading fairy tales to children.
g. stays... in some form
h-o exist aplenty and are misused outside the sanctuary of science
m. can be used in science much more than it is..

I a. this post as an organizing template ! (love)