As simply as possible …
Do we know that the Sun will rise tomorrow because it has risen in the past? No. Hume’s psychological account of inductive inferences is mistaken, for it misstated the problem. Somehow empiricists have taken Hume as the final word that the justification for the belief that the Sun will rise tomorrow is that the Sun has risen in the past. It is easy to undermine that argument, for there is no logical inference made. We know the Sun will rise tomorrow because we know why it rises. We have an explanation: the Earth rotates on its axis roughly every 24 hours, and we have an explanation for why that happens, and so on. The rising Sun has led us to seek an explanation, and that explanation is our ‘justification,’ for if the Earth rotates on its axis roughly every 24 hours, then the Sun will rise tomorrow.
The logical content is transmitted from the conditional “if” to the “then,” for while the phrase ‘the Sun will rise tomorrow’ is clearly not true when understood in its broadest sense (the Sun does not ‘rise’, solar eclipses are infrequent events, and people in the far North experience no sunlight for months at a time), when understood colloquially, it is but an observation report of the Sun rising in the East when viewed from a particular vantage point at a particular time. In other words, it would be like saying “If all dogs are brown, then all other things being equal, an individual will, upon seeing a dog, report that it is brown.”
Conditional knowledge, however, is in no way justified by appealing to the explanation. Another explanation about laws of gravitation is necessary. This new explanation requires another explanation, and so on, creating an infinite regress of explanations. This conditional knowledge is in no way justified, for our explanations have in the past been false, and there is no way to know if our explanations are true, for explanations always have a logical content that extends far into the future and past, discussing events that we will never have a chance to observe.