‚ÄčI was searching for the opposite of white out of curiosity. I read many writings, I went through many definitions. Great philosophy, difficult psychology, I found nothing like them in those. If you ask someone “what is the opposite of white”, they usually answer “black”, but that’s not the opposite, it is just another “color” (well, let’s say black and white are colors), so they are in the same category and just not the same.

It’s the same with pretty much anything else people call “opposite”, they don’t really say something really contrary to x, but just another word that is in the same category as the word x.

But then again, if I say “what is the opposite of black” and someone says pelican, it’s not really true, though it is in a really other category and really “contrary” to black because it is something totally different.

So, what exactly is “opposite” defined as in everyday-language ? Is it, like I guess, “in an ordered line (e.g. for visible colors the energy of the light) of things of the same category the thing that is the farthest away from the thing that I want to name the opposite to”? And then again, what would a really contrary opposite be defined as, where it doesn’t belong to the same category: Is this possible after all?

This question, on the surface, is more about language than philosophy, although I think it does have philosophical implications deeper down.

I would say you are correct. Things must be linked in order to be opposed. When we characterize two things as opposites, we mean they are contrasting modes of a single phenomenon.

There are some very significant philosophies based on the concept of opposition. The largely defunct, but still influential Zoroastrianism revolved around the opposition between “good” and “evil”, while Taoism is all about the dynamic union between opposing qualities such as male and female, hot and cold, light and dark, and so forth.

Aristotle in his Nicomachean Ethics spoke of vices as opposite extremes, with the virtuous ideal in the middle. One example I recall are the opposite extremes/vices of “fear” vs. “overconfidence”. The midpoint or golden mean in this framing would be the virtue, in this case, “courage”. The opposing extremes, or vices, would both be undesirable, if in excess.

So in Aristotle’s ethics it seems there is more of a continuum in play, with opposite behaviors and/or attributes visible at the extremes.

What if we think like this?
The opposite of “black” is just “non-black”.
If you want to think of it in terms of a test, try to imagine an object that would be a counterexample to the the claim that “everything is black”. A white ball would prove the sentence false, but so would a red ball or a green one.

One obvious part of the answer is that the opposite depends on the context, and that not all contexts allow for the existence of the opposite. In some contexts, the opposite of 0 is 1, but in other contexts, the opposite of 0 is infinity, which might not even exist in the corresponding context.

It may look like the set of all non-white colors would be the opposite of white, but sets of colors might not even exist in the context of the question. Note that the context is often implicit, which is one part of the explanation why opposites are often not unique. In some contexts, there are also different kinds of opposites (inverse elements of different operations, corresponding element in a dual order, …), hence even when the context is explicit it can happen that it’s unclear what it meant by the opposite.

Some people are fond of saying the opposite of love is indifference, not hate.  This is an error.  The opposite of any emotion is its counter emotion.

Love is the opposite of hate.
Joy is the opposite of sorrow.
Courage is the opposite of fear.
Indifference is the absence of any emotion.

Opposition is often confused with absence, and for good reason.  A true opposite of anything is the negative of that thing.  This is obvious with numbers.  Five is the opposite of negative five, not the opposite of zero.  That’s why love is the opposite of hate, not indifference.

But some concepts don’t have negatives, yet still appear to have opposites.  Everyone knows the opposite of white is black – right?  But white is light, and black is the absence of light – zero light.  There is no negative light that we are aware of (though some physicist will undoubtedly propose it).  Heat has no negative.  Cold is simply the absence of it.  Existence itself has no negative.  There is only existence or non-existence – which is absence.  We will always think of these things as opposites: white and black, hot and cold, existence and absence.  We could call this a pseudo-opposite or acknowledge two kinds of opposites:

Opposite of negativity
Opposite of absence

Does this mean we can call indifference the opposite-of-absence of love?  Nobody can stop us, but if we do that, we will confuse things that have negatives with things that don’t have negatives.  If a concept has a negative, then its negative should be recognized as its opposite.

A definition is in order:
Opposition is the relationship of two concepts on a common axis with a midpoint between them.  The axis represents a quality in which both concepts participate.  The midpoint represents a place where neither exists, or a portion of each exist equally.  e.g.  Left is the opposite of right, the center being the midpoint.  Left is also the opposite of right with the subject being the midpoint – the person evaluating leftness and rightness.  Likewise, front and back, above and below, up and down, high and low.  Acid is the opposite of alkaline, neutrality being the midpoint.  Good is the opposite of evil, ethical neutrality being the midpoint.  If the two concepts are on an incremented axis, they must be equidistant from the midpoint, such as five and negative five.  Opposites cannot be identified without identifying that quality which is the criterion for opposition.

An opposite may be absolute or relative.

1.  An absolute opposite has an absolute midpoint.
e.g.  Positive numbers are the absolute opposite of negative numbers, zero being considered an absolute midpoint.
    -4, -3, -2, -1, 0, 1, 2, 3, 4
The set of all positive numbers is the absolute opposite of the set of all negative numbers.
A particular positive number is the absolute opposite of its corresponding negative.

An inward spiral is absolutely opposite in motion to an outward spiral, zero motion being considered an absolute midpoint.
If a spiral is seen apart from motion, then the mirror image of that spiral is its opposite, the surface of the mirror being the midpoint.
If a single spiral is viewed from opposite sides, the spiral is the midpoint, and the views of it are opposite.
If two mirror image spirals are on the same plane, then they are bilaterally symmetrical, with a midline between them.
If they are on unrelated planes, then they are opposite in shape alone, and not in location.  Their opposition consists of a one-to-one correspondence of all points on them, and the midline is reduced to an abstraction – an imaginary line between two lists of corresponding points.
Any two things in absolute opposition imply an absolute midpoint or midline between them.

2.  A relative opposite implies an arbitrary midpoint.
e.g.  3 is the opposite of 7 relative to 5.
1 2 3 4 5 6 7 8
France is opposite Germany relative to the Rhine River.
France is opposite Poland relative to Germany.
A particular black is the opposite of a particular white relative to a particular gray midpoint.
Hot is opposite cold only relative to a degree of heat arbitrarily regarded as neutral.
Fast is the opposite of slow, only because fast exceeds an arbitrarily chosen speed, and slow is less than that speed.

Anything that has a negative value has an opposite.  If something has no negative value (such as light and heat) then its absence can be considered its opposite, assuming an arbitrary neutral midpoint.  Sometimes two things that have no midpoint are still thought of as opposites.

e.g.  Right and wrong are seen as opposites, though they appear to have no midpoint.  But right and wrong are adjectives modifying declarative statements.  A legitimate declarative statement is either right or wrong;  it can’t be neutral.  Therefore the absence of a declarative statement must be seen as the midpoint – a place of zero rightness and zero wrongness.

Some things either don’t have opposites, or their opposite is identical to them.  A ray or vector in one direction is the opposite of the same ray or vector going the other direction.  But if direction is not considered, the ray or vector is reduced to a line.  What is the opposite of a line?  Its mirror image is identical to it.  If the absence of a line were the opposite of a line, then the absence of anything would be its opposite.  The distinction between absence and opposition would be obliterated.  The opposite of any number would be zero.  Its negative would be just another number, the opposite of which is also zero.

In Computer Science, we know, there are only two values 1 and 0. Anything other than 1 is not 1 and the same for 0. Since the domain of values is just two, 1 is opposite to 0 and vice versa.
if True:
is a logical statement in a language, suppose. The if block executes if the condition is True, in the sense 1. It does not work if it is not True. When we take it to our life scenario, our domain of values is negative to positive infinity and so this statement to be executed needs more specific conditions. If not True is not just 0, its much more. To conclude, something stands opposite to something according to situations, like our attitude which changes according to circumstances.

If a thing has a negative value, then its negative value, and not its absence, should be considered its opposite.  Male is the opposite of female, not sexlessness.  Likewise, happiness should be seen as the opposite of unhappiness, not emotional neutrality.  If emotional neutrality is seen as the opposite of happiness, then the midpoint is “half-as-happy”, which is still happiness.  The same is true of love, indifference, and hate.

These are all my concepts that I framed so as to waste time. Ideologies and logic changes, like everything do, even people, by seconds.

But still I doubt, is black opposite to white?