Okay I follow you on heat/cold and light/dark. Defining evil as an absence of Good is pretty popular, and defining evil as an absence of God
is pretty popular too, but gets a bit messy, depending on your god-concept. Most God type concepts (Abrahamic monotheism) hold that God is all-powerful and all-knowing, so even if this evil only exists when God is not around, God must have intended it, and has some purpose for it.
Shakier is the more recent idea that evil comes from Lucifer and other Fallen. If this is the case then of course God is responsible, having created them, and Hell, etc, and particularly in having cast them out ... or a little further back for having created humans, which some legends hold caused the revolt in Heaven ...
More ethically than theologically, let's define good acts as those which benefit all (aka true altruism). What then are acts which benefit none, or those which only benefit a small group? Are these acts evil, or is inaction itself the evil?
Historical examples such as the ever-present figure of Hitler suggest that it is actions which benefit no one which are evil ... but if their intent was to benefit themselves or a group of others, and they failed through confusion or just failed their tasks ... what then ?
As to 0 and infinity, I can tell you that quite a lot of our advanced mathematics are built on these concepts. The ability to define a quantity as none, or as immeasureably large or small is vital to calculus (The beginnings of which mark the boundery of my knowledge of mathematics).
To answer the question of whether zero or infinity 'exist' you have to take on the much more vexing question of what is mathematics, what does it measure, and is any of it 'real'. Does such a thing as a geometric (Euclidean, please) square exist in the world we inhabit?
Penrose takes this up in his recent work, which I am slowly reading through.. You might find it quite interesting:
Roger Penrose, _The Road to the Universe_
All very interesting, no ?
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