1. When living, you are necessarily always acting.
2. In scenarios and cases involving decision-making, deciding not to act is not only a decision, it's an action -- if only a negative one.
3. By living, we are slaves to physics.
4. We can choose to what we are slaves, in some cases. If we must be enslaved, then logic currently appears to be a suitable master.
5. Even if we concede that relying on our senses to conclude that our senses are reliable is nonsensical, we still necessarily act on our senses continuously by merely existing.
6. Therefore, we must always act as though we believe that a given option is the most logical, even if we have no idea one way or the other, because "not acting" is still acting, and is often less logical than some other option. Note: This refers to instances in which one action appears more logical than the others -- not instances in which we don't even have leads derived from sensory input.
This illustrates the necessity of pragmatic action in life; just because I am humble and possess a finite, relative perspective of the world does not mean that I cannot make decisions to improve reality. I don't have to believe anything to be true in order to act as though I do. Furthermore, because action is an inevitable by-product of existing, that which is perceived as the most logical out of all potential actions will come to be the logical action, while all other actions, in spite of occupying a gradient of degrees of logicality, will come to all be illogical actions. This is because, even though these latter actions differ in to what extent they are logical, they all share the quality of having not been chosen.
Note, also, that my supposition that relying on my senses to conclude that my senses are reliable is nonsensical is itself relying on my senses, as is this very statement. In other words, there is an infinite regress of assumption that must necessarily be made in order to exist as an intelligent organism, so whether something is true is entirely irrelevant to how much work we should put into implementing it in our daily lives.