'consist' vs 'subsist'

Question

From this answer, I learned from Collins that consist is a synonym for subsist.

[D3.] subsist - (followed by in) to lie or reside by virtue (of); consist

1. What are the similarities and differences, between consist and subsist?

2. Can consist interchange with subsist? Eg: p 13, How the Law Works, by Gary Slapper:

In what does the merit of legal science – or the ‘art of Law’ as it was referred to by Sir Edward Coke – subsist? It subsists in the accumulated experience and expertise that enable its professionals to do many important things.

3. If I try to change subsist to consist, what happens to the trailing in (coloured in grey)?
In other words, does the Collins definition imply

4. subsist in = consist  or  
5. subsist in = consist in   (ie: the preposition in is added to both sides)   ?

Answer 1

Subsist derives from Latin literally meaning to stand still or to remain. Sub means "under", and sistere means "to stand" or "to place"; imagine placing a piece of paper under a weight so that it does not leave.

Subsist is generally used to indicate survival on a minimum of resources, but can also be used to indicate something continues (retaining a certain state) or even just exists. In your example, subsist seems to be used to indicate persistence. The "art of law" continues, or survives in the accumulated experience and expertise.

Note that subsist does not require a complement. You can simply say "The art of law subsists." In your example, the complement "in" was added to indicate where the art of law persists.

In contrast, consist derives from Latin literally meaning to stand together. Con- derives from the Latin cum, meaning "with" or "together," and again sistere means "to stand."

Consist is used to indicate either what a subject is composed of, or what it is comprised in.

In its modern usage, consist always requires a complement indicating either what the subject is composed of, or what the subject is included within.

Consist also has an older definition allowing it to indicate that something simply exists, but this is an obsolete use of the word.

From Webster's Revised Unabridged Dictionary (1913):

To Consist, Consist of, Consist in. The verb consist is employed chiefly for two purposes, which are marked and distinguished by the prepositions used. When we wish to indicate the parts which unite to compose a thing, we use of; as when we say, Macaulay's Miscellanies consist chiefly of articles which were first published in the Edinburgh Review." When we wish to indicate the true nature of a thing, or that on which it depends, we use in; as, There are some artists whose skill consists in a certain manner which they have affected." Our safety consists in a strict adherence to duty."

See also Dictionary.com:

Consist verb (used without object)

1. to be made up or composed (usually followed by of):

"This cake consists mainly of sugar, flour, and butter."

2. to be comprised or contained (usually followed by in):

"Her charm does not consist only in her beauty."

Answer 2

Use "of" with "consists" and "in" with "subsists."

When you say X consists of Y and Z, you are saying and Y and Z together form a new X.

This salad consists of lettuce and tomatoes

You similarly can say "This salad is made of lettuce and tomatoes"

Subsist means to survive, flourish, or have the ability to exist, and is commonly used with abstract things, etc.

In the determination of the relations that should subsist between the new republic and the United States certain definite conditions known as the Platt Amendment were finally imposed by the United States, and accepted by Cuba (12th of June 1901) as a part of her constitution. Reference

Look at the reference, you can use many prepositions after subsist (on, under, etc.) but not of.