The True Meaning of “Aṅguṣṭha-Mātra”: Is the Soul Really Thumb-Sized?

Question

What does the twelfth śloka mean—especially the phrase “aṅguṣṭha-mātraḥ puruṣaḥ”? Is the soul really the size of a thumb?

Answer

This twelfth śloka seems a little difficult, so let’s look at what exactly is hard in it. It says: “Aṅguṣṭha-mātraḥ puruṣaḥ madhya ātmani tiṣṭhati īśānaḥ bhūta-bhavyasya…”
It means: the Supreme Person, the Supreme Soul, is “aṅguṣṭha-mātra,” and is situated in the center of the body, in the space of the heart. He is the ruler of the past, present, and future. One who knows Him never criticizes anyone. This is that very Supreme Soul you asked about.

Most of this is simple. We already know that the Supreme Soul is said to dwell in the cavity of the heart. And we also know that He governs the past, present, and future. Whatever happens takes place by His will, not ours. That part is easy.

The difficulty is in the phrase aṅguṣṭha-mātra. The common understanding is that the soul sitting in the heart-space has a size equal to the thumb. People say: the human heart-space is of a certain size, and the soul inside it is of “thumb-size.”
Then another question arises: If this is so in a human body, then what about an ant?
In an ant, the heart-space is tiny—so does the soul there also become tiny? And what about an elephant? Its heart-space is huge—so is its soul huge too?
These explanations are often given, but they are not very convincing.

When I looked into the Vedas for the meaning of aṅguṣṭha-mātra, I found a reference connected to a sage named Śākalya. He breaks the word aṅguṣṭha into three parts: aṅg + u + iṣṭha.
“Aṅg” means “in the limb,” “in the body,” or specifically “in the heart-cavity.”
“U” (the long ‘ī’ sound in some places) is a Vedic term used as a name for the Supreme Being.
“Iṣṭha,” from the root stha, means “to stay,” “to remain,” “to be situated.”

When these three parts are rejoined—aṅg + u + iṣṭha—we get “aṅguṣṭha.”
So the phrase aṅguṣṭha-mātra actually means:
“The one who is simply present, who merely exists in the heart-cavity.”
“Mātra” indicates “only this much,” meaning mere presence, not size.

To understand this, think of a catalytic agent. Hydrogen and oxygen don’t form water just by being put together. Only when electricity passes between them does water form. Electricity functions as the catalytic agent.

In the same way, everything is being done by prakṛti—by the body, senses, mind, intelligence.
We speak because the body acts.
We think because the mind acts.
We decide because the intellect acts.
All of this is prakṛti at work.
But prakṛti can function only when the soul is present—just like the catalytic agent.

If the soul were not present, the body could not perform anything at all.
So “aṅguṣṭha-mātra” means:
The soul is merely present—its presence is essential, but it is not doing the actions. Prakṛti is doing everything.

The Supreme Soul sits in the heart-space like a catalytic agent—present, allowing everything to function. And the person who realizes this never criticizes anyone. Why would he? He knows that the Supreme is present and active behind everything. When one is free from body-consciousness, criticism naturally disappears.

This is the meaning of the twelfth śloka.