To investigate on the substance do you use a representation of the substance or not?

It is impossible to do otherwise with all but the most basic concepts (geometrical things which you can define exhaustively through axioms and almost nothing else). If I see a tree, I do not observe the tree, but the photons it releases in one direction.

More pertinently, you need to use a simplification of an object to reason about it. Valid reasoning needs to deal with all of the relevant (for some appropriate definition of 'relevant' - I speak English but am not schooled in philosophy) factors in an object, and there is simply no way to do that if you discuss the whole of the object unsimplified without wasting all of your time on trivialities. It is possible to draw meaningful conclusions about a simplified representation of an object.

EDIT:@Additional details - philosophy includes 'ethics', which is very full of substance, and where it is completely impossible to avoid representations because there is no other way to convey the lives of the people involved. The conclusions reached are sometimes somewhat insubstantial ('this is bad' and such) but the philosophy of it is profound.

Well, if I get you right, all I can say is nothing is here to stay forever. The only constant in life is change. Variety is the spice of life. I know, change often brings along with it lots of pain. It's difficult to let go of something you are so used to. But you really do not have much of a choice. I suppose you simply have to learn to accept change gracefully. You've got to move on. If I may draw an analogy, look at the river. If you are flowing with the river, floating on the water and watching the scenery, the scenery will keep changing and life will be exciting. However, if you get stuck in some puddle and don't get out soon, you'll suffer. The water in the puddle will become filthy, the scenery will not change much, all kinds of rubbish will get entangled with you, etc. So, its best to get onto the river and flow along into the ocean. But watch out for the water-falls.

There are all sorts of tricks to help the ego/mind advance in it reasoning and expansion but in the end even those schemes must be toppled until only pure reason is left and that requires the suspension of all mental structures. They become ever more subtle until they are fine enough to waft away on the slightest breeze of intuition and then we are able to know directly sans the filters of the senses and ego/mind. In that state, pure being directly knows wherever It goes.

I vow to be the one in a hundred thousand who attain that state though it take me ten thousand incarnations, or more.

Namaste'

Try the `chemistry` forum

this is no place for these a/illusory queries good luck there.

I agree..children are really substantial..but/ and

as you don`t say to what you refer, we can only infer and

not get anywhere in answering you nia.

you are using metaphor...please feel supported..we all feel low when things are outof our hands

but it looks like someone has given you a suitable answer.LOL.

Making models help. But everyone knows that. So what is the deeper part of your question? There is one, isn't there?