Step 1: Understanding Hume’s Principle of Causality.
David Hume’s principle of causality suggests that causation is based on the observation of regular succession and contiguity between events. According to Hume, we cannot observe necessary connection directly; rather, we infer causality through the regular conjunction of events.
Step 2: Analyzing the Options.
- 1. The two events are in conjunction with each other: This is true. Hume argued that for one event to be the cause of another, the events must occur together (conjunction).
- 2. The two events are in proximity to each other: This is true. Proximity, or temporal nearness, is essential in Hume’s view of causality.
- 3. The two events have necessary internal connection: This is incorrect. Hume denied the existence of a "necessary connection" that we could observe directly; he argued that causality is inferred, not seen.
- 4. The two events are contiguous: This is true. Contiguity refers to the closeness of events, which Hume considered important for causality.
Step 3: Conclusion.
The correct answer is 3. The two events have necessary internal connection.
Final Answer:
\[
\boxed{\text{The correct answer is 3. The two events have necessary internal connection.}}
\]