Answer:
The word base here seems to mean that Victor Frankenstein refused to despise himself, think of himself as lowly, as the monster may have seen or thought him to be.
The dictionary defines "base" as something that is low, or the source of something, the beginning point (as a noun) and as a verb, it means a 'foundation' of some sort.
Victor's refusal to make another monster is a good argument because, as far as he knows and is concerned, the monster had only brought pain and suffering to humans. And so, if there is another like him, then there is no saying what will happen in the future. One monster is better than two.
Explanation:
Mary Shelley's "Frankenstein" is a gothic novel revolving around a young scientist's desire for greater knowledge. This led him to create a living creature from dead human parts, akin to the role of a god in giving life to another.
In the given passage from Chapter 16, the monster had requested his creator Victor Frankenstein to create a companion, a female for him. But Victor refused, declaring that it will only <em>"desolate the whole world."</em>
The use of the word "base" in the passage is suggestive of Victor's refusal to be deemed lowly, weak, to despise himself, etc.
The dictionary definition of the word "base" is as a noun, to be the lowest part, the support or source of a thing. And as a verb, it means the foundation, the location, etc.
Frankenstein has a good argument for refusing to create a companion for the monster because then, they will only create more havoc and death to humanity, as that was all the monster had done till now. Victor sees the monster as nothing but an "abhorrence", a mistake (if applicable) and would only lead to the end of the human race in the world.