Philo, in David Hume's Dialogues Concerning Natural Religion, argues not that we can know from the observed imperfections in the world that God has either limited power or limited goodness, but rather that we cannot use our observations of the world to show that God is infinitely powerful and infinitely good. We cannot conclude that God is all-powerful or all-good because the world is full of experiences in the animal and human realm which are clearly not good by our own definition of that word.
The primary assumption Philo makes is that all we have to go on in discussing the attributes of God is our experiences, or the information from the physical world which enters our minds through our senses. This information, based on causality, does not tell us enough about God as the first or primary cause to come to definitive conclusions one way or the other about the attributes of that cause. Causality involves the assumption that things and events have causes, that something causes them to be, and that there is a connection between the cause and the effect which we can determine and understand. One can learn something about the attributes of an entity by examining the nature of the things it has created, or which came out of it.
Accordingly, our experience does tell us much about the nature of the world in which we live and about the nature of our experience in that world, and from the internal reality and responses to that world:
Philo: Observe . . . the curious artifices of nature in order to embitter the life of every living being. The stronger prey upon the weaker and keep them in perpetual terror and anxiety. . . . Man . . . can . . . surmount all his real enemies . . . but does not he immediately raise up to himself imaginary enemies, the demons of his fancy, who haunt him with superstitious terrors and blast every enjoyment of life? (60).
Philo speaks here of the torments of the conscience of terrors of the future...