Final answer:
The statement is false; commas are used between coordinate adjectives that could be joined by 'and', while hyphens are used for compound modifiers before a noun that together express a single concept.
Step-by-step explanation:
The statement is false. You should use a comma between two adjectives when they are coordinate adjectives, meaning that they can be joined by and and the order of the adjectives could be reversed without changing the meaning of the sentence. However, when two adjectives are cumulative (not coordinate), and each adjective alone modifies the noun in a different way, they should not be separated by a comma. Instead, they are often connected by a hyphen if they precede the noun they modify and work together to establish a single concept.
For example, in the phrase "a well-known author," the hyphen is correctly used because "well" and "known" together modify "author." They cannot be separated by a comma or the word and without altering the meaning. This usage clarifies that the author is not well and known, but rather known-well as in widely recognized.
In the second part of the question, an artistic viewpoint by Mark Twain encourages the sparing use of adjectives for stronger writing, but this does not equate to the necessary punctuation usage between adjectives which is the actual subject of the question.