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 ____________ 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 not among the philosophers. Fill in the blank: own, and also by ____________ out that, even within this field.

Introduction / Context:
This cloze question continues the philosophical passage about whether philosophy can be considered a genuine science. It describes how certain critics support their position. The blank occurs after the phrase and also by, indicating what these critics are doing to strengthen their argument.

Given Data / Assumptions:

• The sentence containing the blank reads: and also by ____________ out that, even within this field, there is a growing tendency on the part of certain sciences to separate themselves from philosophy.
• The earlier part of the sentence uses the phrase support their case by pointing to the lack of a general consensus.
• Parallel structure is often used in such sentences: support their case by doing X and also by doing Y.
• Therefore, the missing word must match this pattern.

Concept / Approach:
The underlying grammar point is the use of gerunds (ing forms) after the preposition by. When we say by, it is typically followed by a noun or a gerund (for example, by running, by reading, by pointing). To maintain parallelism with the earlier phrase by pointing to, the correct form must be another ing form that fits with out that.

Step-by-Step Solution:
Step 1: Notice that by is already present before the blank, so we need a noun like form or a gerund.Step 2: The phrase out that strongly suggests the collocation pointing out that.Step 3: The earlier phrase by pointing to supports the idea of repeating pointing as a gerund for stylistic and grammatical parallelism.Step 4: Therefore, the correct completion is pointing, giving by pointing out that.

Verification / Alternative check:
Try inserting each option into the sentence: by point out that (incorrect), by pointed out that (incorrect tense and form), by pointing out that (correct), by to point out that (ungrammatical after by). Only pointing fits naturally and maintains the structure support their case by pointing to... and also by pointing out.... This confirms that pointing is the correct answer.

Why Other Options Are Wrong:
Option A, point, cannot directly follow by when it functions as a verb; it would need to be by pointing or by a point.
Option B, pointed, is a past tense verb and does not fit immediately after by in this construction.
Option D, to point, is an infinitive form; the standard expression is by pointing out, not by to point out.

Common Pitfalls:
Students sometimes overlook prepositions and choose a base verb or infinitive out of habit. Another common error is to ignore parallelism within a sentence. When a sentence presents two activities in a by plus gerund form, the second activity should mirror that structure.

Final Answer:
The correct gerund that completes the phrase by ____________ out that is pointing, so the phrase becomes by pointing out that. Thus, the correct answer is pointing.