The meaning of "would" in the mentioned context?

1. In the right conditions, would happiness and pain come together?



2. Would happiness and pain come together?

For the sake of brevity, can we say sentence 2 when we mean sentence 1?

Answer

The meaning of "would" is more or less the same in both of your sentences, but the two sentences ask different questions and will receive different answers.

Q1: In the right conditions, would happiness and pain come together?

The first sentences explicitly specifies "in the right conditions", so the answer is yes if there are any conditions that would allow happiness and pain to come together, even if those conditions are not happening now or are not likely to ever happen.

There is no specification in the second sentence, so clear answers to the question are likely to be based on current or expected conditions, or answers could specify their own conditions.

Q2: Would happiness and pain come together?

A1: No. (Under some assumed conditions, such as the current situation, or if they could never come together.)

A2: No, not normally. (Specifying that they are unlikely to come together.)

A3: Only under special circumstances. (Noting that there are some conditions that can allow happiness and pain to come together, but that these are the exception rather than the rule.)

If we want to be brief, a better way to express the meaning of the first question would be:

Would happiness and pain ever come together?

Adding "ever" here specifies that the question is asking for any possible circumstances. This expresses the meaning of the first question and is almost as short as the second quotation. Another way to express this question would be to replace "would" with "could":

Could happiness and pain come together?

Using "could" instead of "would" expresses that you are asking about possibilities rather than expectations.