Let's analyze the given sentence fragment from the passage: "The active function __________ the volitional". We need to choose the correct word from the options to fill the blank, ensuring it fits grammatically and contextually.

Understanding the Context of the Active Function

The passage discusses two distinct functions of the human mind. The sentence in question specifically talks about the "active function". It goes on to describe what this active function does: "It is the conscious focusing of the mind [...] some mental problem." This tells us that the blank needs a verb that describes the action or characteristic of the active function.

Analyzing the Grammatical Structure

The subject of the sentence is "The active function". 'Function' is a singular noun. The blank requires a verb that agrees with this singular subject. The phrase following the blank, "the volitional, voluntary thinking", seems to be the object or what the active function is related to.

Evaluating the Options for the Blank

Let's look at the provided options:

• performs: This is a third-person singular present tense verb. It agrees with a singular subject like "function".
• perform: This is a base form or plural present tense verb. It would be used with a plural subject (e.g., "Functions perform") or with pronouns like I, you, we, they.
• performing: This is a present participle. It is typically used as part of a continuous tense (e.g., "is performing", "was performing") or as a gerund/adjective. It doesn't fit directly after a singular subject like "function" in a simple present tense structure describing what it *does*.
• performed: This is a past tense verb or a past participle. The context describes a general characteristic or ongoing function of the mind, not a past action.

Determining the Correct Verb for Active Mentation

The sentence describes what the active function inherently does. The simple present tense is appropriate for describing such a general characteristic or function. Since the subject "The active function" is singular, the verb must also be singular in the present tense. The option that fits this requirement is "performs".

So, the sentence becomes: "The active function performs the volitional, voluntary thinking." This means the active function carries out or executes the volitional type of thinking.

Why Other Options Are Incorrect

• 'perform' is incorrect because the subject "function" is singular.
• 'performing' is incorrect as it requires a form of 'to be' (like 'is performing') to function as the main verb in this context.
• 'performed' is incorrect because the passage describes a present function, not a past action.

Therefore, the correct word to complete the sentence is 'performs'.

Revision Table: Filling Blanks in Passages

Additional Information: Types of Mental Functions

The passage contrasts an "active function" with an implied other function (perhaps passive or involuntary). Understanding these broad categories helps in interpreting the text.

• Active Function / Mentation: As described, this involves conscious, volitional, voluntary thinking. It's about focusing the mind deliberately on a specific problem or subject. This requires effort and control, banishing irrelevant thoughts. It's often associated with focused work, problem-solving, and deliberate study.
• Passive / Involuntary Mentation: While not explicitly detailed for the other function in this snippet, mental activity can also be involuntary. This might include daydreaming, spontaneous thoughts, intuition, or subconscious processing, which occur without deliberate conscious effort or control.

The ability to switch between or utilize both active and passive forms of thinking is crucial for various cognitive tasks.