Short answer: Yes, CT is falsifiable. Here's how to see this. Take a look at the example CT chart. By following the procedures stated in the Theory and Practice document, you can produce and check a CT chart like the example chart. Once you've checked the chart, you can make predictions using CT and the CT chart. From the example chart, for instance, we can see that the person sometimes plays video games and tries to improve and sometimes plays video games while not trying to improve. From the chart and CT, we can predict: "If the person comes to believe that he stably has the ability to be cool, as he conceives of coolness, then he will stop playing video games while not trying to improve." We would measure belief here primarily by the person's belief reports. So we have a concrete procedure that yields specific predictions. In this case, if the person followed various recommendations designed to increase his ability to be cool, ended up reporting that he stably had the ability to be cool, but still reported playing video games while not trying to improve, CT would be falsified.

Longer answer: In practice, almost any specific theory can be rendered consistent with the data by adding epicycles, positing hidden entities, and so forth. Instead of falsifying most theories, then, what happens is this: You encounter some recalcitrant data. You add some epicycles to your theory. You encounter more recalcitrant data. You posit some hidden entities. Eventually, though, the global theory that includes your theory becomes less elegant than the global theory that rejects your theory. So, you switch to the global theory that rejects your theory and you discard your specific theory. In practice with CT, so far we haven't had to add many epicycles or posit many hidden entities. In particular, we haven't had the experience of having to frequently change what we think a person's intrinsic goods are. If we found that we kept having to revise our views about a person's intrinsic goods (especially if the old posited intrinsic goods were not instrumentally useful for achieving the new posited intrinsic goods), this would be a serious warning sign.

Speaking more generally, we're following particular procedures, as described in the CT Theory and Practice document. We expect to achieve particular results. If in a relatively short time frame we find that we can't, that will provide evidence against the claim "CT is useful for achieving result X". For example, I've been able to work for more than 13 hours a day, with only occasional days off, for more than two years. I attribute this to CT and I expect we'll be able to replicate this. If we end up not being able to, that'll be obvious to us and everyone else.

Thanks for raising the issue of falsifiability. I'm going to add it to our CT FAQ.