Final answer:
Justified true belief (JTB) are necessary conditions in epistemology for determining knowledge because they require belief to be backed by justification and truth. Edmund Gettier's challenge to JTB highlights the complexity of defining justification and ensuring that knowledge is truly acquired.
Step-by-step explanation:
The concept of "justified true belief" (JTB) is foundational in epistemology, the branch of philosophy concerned with the nature of knowledge. Justification, truth, and belief are considered necessary conditions for knowledge because they collectively ensure that a statement or proposition is not only believed to be true but has a backing of evidence or rationale, and is actually true in reality. Edmund Gettier highlighted the shortcomings of the JTB account by presenting cases where these conditions were met yet knowledge was arguably absent, leading to the famous Gettier problem. Philosophers continue to debate the intricacies of what constitutes justification and how to buttress the JTB account against Gettier-like exceptions. The fallibility of justification implies that while it makes a belief more likely to be true, it does not guarantee truth; thus, the nature of justification remains a significant topic of inquiry in epistemology.