Step 1: Understanding the question.
The sentence is describing how the views of certain people had been intellectually positioned from the beginning. We need to find the word that best conveys the idea that these views were in complete disagreement or could not be reconciled.
Step 2: Analyzing the options.
(A) parallel: This suggests that the views were in the same direction, which doesn't fit with the idea of intellectual disagreement.
(B) opposed: While this suggests disagreement, it doesn’t capture the intensity implied by "from the beginning."
(C) defined: This is not a suitable option as it doesn’t convey the idea of disagreement.
(D) irreconcilable: This word perfectly fits the context, suggesting that their views were fundamentally at odds and could not be reconciled.
Step 3: Conclusion.
The correct answer is (D) irreconcilable, as it best conveys the idea of views that could never be brought into agreement.