What is the difference?

To rationalize something is to try and make the cause of the event seem like it was something other than the true cause (i.e. to justify, etc). Whereas explaining is simply describing what happened without attempting to shift the actual cause to something else.

In truth they are very closely related and are often used interchangeably especially in situations where two people have different opinions as to the cause of an event, etc. For example, I may believe that the actual cause of event Z is A but you believe that the actual cause is B. So while I feel like I am explaining the event in terms of A, to you it seems as though I am rationalizing because you still believe that the actual cause is B. It’s all a matter of perception.

Rationalize = to ascribe (one's acts, opinions, etc.) to causes that superficially seem reasonable and valid but that actually are unrelated to the true, possibly unconscious and often less creditable or agreeable causes.

Explain = to make plain or clear; to tell what actually occurred

Hope that helps some!

What "gatormba" just wrote was explaining.

Rationalizing usually involves explaining something to yourself when deep down you know that what you are explaining is wrong. I'm constantly trying to rationalize more survival purchases when deep down I know I should probably start thinking about my regular bills first.

I asked Google to define rationalize, and liked the first answer it showed: "to pretend that one’s desires are caused by impartial reasoning".

Sue