a way to prove a fact that it Contains exceptions , is this flawed ? and how ?

The passage you've presented contains several logical flaws, which can be categorized as follows:

1. **Equivocation Fallacy**: The passage seems to equate facts and truth without adequately distinguishing between them. A "fact" is an objective reality based on current evidence and observation, while "truth" is often used in a more philosophical sense. The argument blurs these concepts, leading to confusion about the nature of facts and truth.

2. **Straw Man Fallacy**: The argument presents an exaggerated notion that "a pure truth that has absolutely no exceptions and doesn't develop" is sought, when in reality, most scientific and philosophical inquiries understand truth as provisional and subject to change with new evidence.

3. **Circular Reasoning**: The conclusion ("the only pure truth is that pure truth changes") seems to be a restatement or reformulation of earlier premises without providing additional support. It assumes the conclusion within the premises rather than proving it.

4. **Overgeneralization**: The claim that a fact must change by gathering more knowledge doesn't account for facts that remain stable despite new evidence. While some facts may become more nuanced, others, like mathematical truths, do not change with new knowledge.

5. **Begging the Question**: The passage assumes from the start what it sets out to prove—namely, that all facts are inherently mutable and contain exceptions. This assumption is built into the argument rather than demonstrated.

6. **Conceptual Confusion**: By concluding that "we consider 'facts' is never truly a timeless truth," the argument conflates the understanding of facts as subject to change in light of new evidence with the idea that they are inherently untrue or unreliable, which is misleading.

In summary, the passage contains logical fallacies that undermine its argument. It relies on ambiguous definitions, circular reasoning, and unsupported generalizations, leading to a flawed and convoluted conclusion about the nature of facts and truth.