One sceptical rejoinder to those who claim that sensory perception is cognitively penetrable is to appeal to the involvement of attention. So, while a phenomenon might initially look like one where, say, a perceiver’s beliefs are influencing her visual experience, another interpretation is that because the perceiver believes and desires as she does, she consequently shifts her spatial attention so as to change what she senses visually. But, the sceptic will urge, this is an entirely familiar phenomenon, and it hardly involves some special or theoretically important cognitive effect on sensory perception. Even supposing that the sceptic is correct about cases that are accurately described in this way, the rejoinder oversimplifies the possible roles that attention may play in mediating cognition and perception. This paper aims to identify these different roles, and by emphasis on empirical research on feature-based and object-based attention. What emerges is a plausible and well-evidenced mental schema that describes attention-mediated cognitive penetration. At the very least, the burden of proof is shifted to the sceptic, as he then must show that there are no mental phenomena involving attention in the more nuanced ways described here.