Investing requires speculating. Investing as a contributor said on a different panel is outlaying capital. Speculating in making a guess (informed or otherwise) about the future. Investment decisions take place in a market place with incomplete information. Making a guess about the future is thus a necessary condition for completing the investment function.

From some of the comments, it appears the question raised tries to label investing as positive and speculating as negative. When one adopts the distinction as implied in the original question, a discussion of risk is required to support the distinction (high risk bad, low risk good). I believe this is not a constructive way to think about the investment function. Investment professionals have acquired and utilize tools necessary to make informed decisions with limited information. To throw out speculation entirely is to throw an entire body of knowledge in probabilities that civilization has developed over centuries and that a number of physical sciences rely on to make advances in their respective fields.

The distinction should be between investors who take the time to formulate and articulate an investment philosophy and process and spend considerable effort in understanding their investment opportunities before committing capital, and those who don't. During times of volatility the first group is likely to remain calm and let their numbers guide them; the second group is likely to head for the exit at any cost.

As with all professions, being honest with oneself and others is a sure way to remain on the positive side of any distinction.