Ben, in English terms?
I had this same question before on Buddhachat and we concluded that it's a circle. Because to even develop that small amount of right view requires some amount of effort. So, where did that first tiny amount of right view come from, if not some previous effort? And where did that previous effort come from, if not from a previous insight? Many rebirths into the past? Infinite rebirths?
You can trace it back further and further, and ask, "So, what is the ORIGINAL view or effort or other thing that spurred the rest on?" And that's really just a silly question. The question ends up being a futile investigation into the relationship between the conditioned and the unconditioned.
Anyway, there are lots of complicated, even convoluted theories of motivation (see ). But there are some obvious causes, like a stable living environment, a sense of self-worth, and a sense of purpose.
When people ask, though, what the cause of effort is, I don't think they're talking about the kind of effort that's merely conditioned by previous factors, like the kind of mental stability that comes from simply being lucky, else we could all just wait for our time to be motivated to randomly float along. What they mean is: What is the cause of real effort? Where can I find the genuine power to change my life?
And the answer is that there is no magic to it or any secret than what you already know. Any motivational capacity you have, you are already aware of and it is up to you to discover it and act. Somebody describing the mechanics of effort, trying to adopt a certain religion, etc., won't change your life significantly. It is up to you to act to change. Because a lack of motivation itself is not a lack of energy, but it's energy that is either being unused or misdirected.
The best things in life aren't things.