In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives. Those who argue in this way support their case by pointing to the lack of a general consensus of opinion which obtains in many parts of the field which the philosopher regards as his own, and also by pointing out that, even within this field, there is a growing tendency on the part of certain sciences to separate themselves from philosophy and become independent. Thus the psychologist and the logician are sometimes very anxious to have it understood that they belong among the scientists and ___________ among the philosophers. Fill in the blank: among the scientists and ___________ among the philosophers.

Introduction / Context:
This cloze question deals with the contrast between scientists and philosophers in the passage. Some disciplines are keen to stress that they belong in the camp of the scientists rather than in the camp of the philosophers. The blank appears in a simple but important contrastive structure.

Given Data / Assumptions:

• The sentence reads: they belong among the scientists and ___________ among the philosophers.
• The structure suggests a contrast: they belong among one group and not among another.
• The missing word must therefore express negation in a grammatically appropriate way.
• The options are no, not, nothing and none.

Concept / Approach:
The concept here is the use of simple negation words. In English, we commonly say belong among X and not among Y to indicate inclusion in one group and exclusion from another. The word not directly negates the phrase among the philosophers, whereas other options do not fit this pattern.

Step-by-Step Solution:
Step 1: Mentally complete the sentence using natural English: They belong among the scientists and not among the philosophers.Step 2: Test the other options: and no among the philosophers, and nothing among the philosophers, and none among the philosophers.Step 3: Observe that only not produces a correct and idiomatic expression.Step 4: Select not as the correct word for the blank.

Verification / Alternative check:
The phrase belong among the scientists and not among the philosophers is standard and appears frequently in similar contexts. Other choices either require additional nouns (for example, no philosophers, none of the philosophers) or change the meaning. The correct structure is a direct contrast using not.

Why Other Options Are Wrong:
Option A, no, would require a noun after it (no philosophers) and does not fit directly before among.
Option C, nothing, is a pronoun meaning no thing and cannot be used simply before among in this way.
Option D, none, would typically need to be part of a phrase like none of the philosophers, which is not the given structure.

Common Pitfalls:
Some learners confuse no and not, using them interchangeably. However, no usually modifies a noun, while not negates verbs, adjectives or prepositional phrases like among the philosophers. Forgetting this distinction leads to ungrammatical sentences.

Final Answer:
To express that the disciplines wish to be counted among scientists and excluded from philosophers, the sentence must read and not among the philosophers. Hence, the correct answer is not.