The reason this philosophy [i.e. empiricism] is likely true or else the best one within the competing marketplace of ideas is that those who attack it, cannot do so unless data comes to them via one of their 5 physical senses, and they send out data intending to stimulate one of the 5 physical senses. If you are using empirical data to disprove empiricism, that is sort of like biting the hand that feeds you, isn’t it?
I should start by saying: although there are probably more sophisticated arguments for empiricism, at this point I'm just assuming porphyryredux means traditional empiricism. After all, it's not as if porphyryredux offers anything more.
1. Who uses "empirical data to disprove empiricism"? Who does he have in mind or what arguments does he have in mind?
2. As others like William Lane Craig have pointed out, empiricism is too narrow. It would exclude logical truths, mathematical truths, moral truths, aesthetic truths, etc.
3. Why should we think our sensory experience is a reliable source of knowledge anyway? Something like Plantinga's EAAN could be relevant for the atheist, for instance. What about arguments for solipsism, to take another example?
4. Why couldn't empiricism coupled with atheism logically lead to a denial of morality, value, meaning, purpose, etc.?
5. Also, what if the empirical data give us conflicting facts or truths?
6. Likewise, there's no empirical data for the existence of certain objects (e.g. the mutliverse, theoretical sub-subatomic particles). Presumably there never can be empirical data for the existence of say sub-subatomic particles either, at least short of building a particle accelerator the size of the solar system.
7. Finally, here is another way to look at empirical knowledge, and if true then it seems our knowledge is mainly a matter of probabilities rather than proofs. If so, then I presume probability type arguments for theism or against atheism would be relevant (e.g. Tim and Lydia McGrew, Richard Swinburne).