Light of Heavens

Composition of Human Body

Imam Jaʿfar al‑Ṣādiq’s (AS) statement that “whatever is in the earth is also in the human body, but in different proportions” is one of the most remarkable examples of his scientific foresight. When expanded and placed in historical and scientific context, it becomes clear how far ahead of his time he truly was.


The Imam taught to his students:

  • Humans are created from the earth.
  • Every element found in the earth also exists in the human body.
  • These elements appear in different proportions:
  • Four in large quantities
  • Eight in small quantities
  • Eight in minute quantities


This is an astonishingly accurate description of what modern biochemistry confirms.  Modern science shows that the human body is composed of the same elements found in the Earth’s crust:


  • Major elements (large quantities): oxygen, carbon, hydrogen, nitrogen
  • Secondary elements (small quantities): calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, iron
  • Trace elements (minute quantities): zinc, copper, iodine, selenium, manganese, molybdenum, cobalt, chromium, and others


These categories map precisely onto the Imam’s three‑tiered description.


Why was this extraordinary in the 8th century?

In the Imam’s time:

  • Chemistry did not exist as a science.
  • No tools existed to analyze the elemental composition of the human body.
  • The periodic table was still 1,000 years away.
  • Biological chemistry was completely unknown.
  • Dissection was rare and did not reveal elemental composition.
  • Aristotle’s Four‑Element theory dominated scientific thought.


Yet the Imam described:

  • The elemental nature of the human body
  • The correspondence between Earth’s elements and human composition
  • The proportional distribution of elements
  • The existence of trace elements
  • These insights were not discovered scientifically until the 18th and 19th centuries, when modern chemistry emerged.
  • Alignment with modern biochemistry


Today, we know that:

  • The human body contains over 20 essential elements.
  • These elements originate from the Earth’s crust and environment.
  • Life depends on precise proportions of these elements.
  • Even trace elements (like iodine or selenium) are vital for survival.
  • Imbalances in these elements cause disease.
  • The Imam’s statement anticipates all of this with remarkable clarity.


Philosophical and theological depth

The Imam’s teaching also carries a deeper meaning:


  • Humans are materially connected to the Earth.
  • The same building blocks that form mountains, soil, and minerals form the human body.
  • This unity reflects the Qur’anic teaching: “We created you from the earth” (Qur’an 20:55).
  • It also reflects the idea that the human being is a microcosm (al‑ʿālam al‑ṣaghīr) of the universe.
  • His explanation bridges science, philosophy, and spiritual anthropology.


Within the Shia understanding, this is attributed to ʿilm ladunnī—knowledge granted directly by Allah (SWT) to His chosen Representatives.