After Agassiz came to the United States, he wrote prolifically on polygenism, which holds that animals, plants, and humans were all created in "special provinces" with distinct populations of species created in and for each province, and that these populations were endowed with unequal attributes.
Agassiz denied that migration and adaptation could account for the geographical age or any of the past.
Adaptation takes time; in an example, Agassiz questioned how plants or animals could migrate through regions they were not equipped to handle.
According to Agassiz the conditions in which particular creatures live "are the conditions necessary to their maintenance, and what among organized beings is essential to their temporal existence must be at least one of the conditions under which they were created".
Agassiz was opposed to monogenism and evolution, believing that the theory of evolution reduced the wisdom of God to an impersonal materialism.

Agassiz was influenced by philosophical idealism and the scientific work of Georges Cuvier.
Agassiz believed one species of humans exists, but many different creations of races occurred.
These ideas are now included under the rubric of scientific racism.
According to Agassiz, genera and species were ideas in the mind of God; their existence in God's mind prior to their physical creation meant that God could create humans as one species, yet in several distinct and geographically separate acts of creation.
Agassiz was in modern terms a creationist who believed nature had order because God created it directly.
Agassiz viewed his career in science as a search for ideas in the mind of the creator expressed in creation.

Agassiz, like other polygenists, believed the Book of Genesis recounted the origin of the white race only and that the animals and plants in the Bible refer only to those species proximate and familiar to Adam and Eve.
Agassiz believed that the writers of the Bible knew only of regional events; for example that Noah's flood was a local event known only to the regions near those populated by ancient Hebrews.

Stephen Jay Gould asserted that Agassiz's observations sprang from racist bias, in particular from his revulsion on first encountering African-Americans in the United States.
However, others have asserted that, despite favoring polygenism, Agassiz rejected racism and believed in a spiritualized human unity.
Agassiz believed God made all men equal, and that intellectualism and morality, as developed in civilization, make men equal before God.
Agassiz never supported slavery and claimed his views on polygenism had nothing to do with politics; however his views on polygenism emboldened proponents of slavery.

Accusations of racism against Agassiz have prompted the renaming of landmarks, schoolhouses, and other institutions (which abound in Massachusetts) that bear his name.
Opinions on these events are often mixed, given his extensive scientific legacy in other areas.
In 2007, the Swiss government acknowledged his "racist thinking," but declined to rename the Agassizhorn summit.
In 2017, the Swiss Alpine Club declined to revoke Agassiz's status as a member of honor, which he received in 1865 for his scientific work, because the club considered this status to have lapsed on Agassiz's death.
In 2020, the Stanford Department of Psychology requested to remove a statue of Louis Agassiz from the front façade of its building.
After Agassiz came to the United States, he wrote prolifically on polygenism, which holds that animals, plants, and humans were all created in "special provinces" with distinct populations of species created in and for each province, and that these populations were endowed with unequal attributes. Agassiz denied that migration and adaptation could account for the geographical age or any of the past. Adaptation takes time; in an example, Agassiz questioned how plants or animals could migrate through regions they were not equipped to handle. According to Agassiz the conditions in which particular creatures live "are the conditions necessary to their maintenance, and what among organized beings is essential to their temporal existence must be at least one of the conditions under which they were created". Agassiz was opposed to monogenism and evolution, believing that the theory of evolution reduced the wisdom of God to an impersonal materialism.
Agassiz was influenced by philosophical idealism and the scientific work of Georges Cuvier. Agassiz believed one species of humans exists, but many different creations of races occurred. These ideas are now included under the rubric of scientific racism. According to Agassiz, genera and species were ideas in the mind of God; their existence in God's mind prior to their physical creation meant that God could create humans as one species, yet in several distinct and geographically separate acts of creation. Agassiz was in modern terms a creationist who believed nature had order because God created it directly. Agassiz viewed his career in science as a search for ideas in the mind of the creator expressed in creation.
Agassiz, like other polygenists, believed the Book of Genesis recounted the origin of the white race only and that the animals and plants in the Bible refer only to those species proximate and familiar to Adam and Eve. Agassiz believed that the writers of the Bible knew only of regional events; for example that Noah's flood was a local event known only to the regions near those populated by ancient Hebrews.
Stephen Jay Gould asserted that Agassiz's observations sprang from racist bias, in particular from his revulsion on first encountering African-Americans in the United States. However, others have asserted that, despite favoring polygenism, Agassiz rejected racism and believed in a spiritualized human unity. Agassiz believed God made all men equal, and that intellectualism and morality, as developed in civilization, make men equal before God. Agassiz never supported slavery and claimed his views on polygenism had nothing to do with politics; however his views on polygenism emboldened proponents of slavery.
Accusations of racism against Agassiz have prompted the renaming of landmarks, schoolhouses, and other institutions (which abound in Massachusetts) that bear his name. Opinions on these events are often mixed, given his extensive scientific legacy in other areas. In 2007, the Swiss government acknowledged his "racist thinking," but declined to rename the Agassizhorn summit. In 2017, the Swiss Alpine Club declined to revoke Agassiz's status as a member of honor, which he received in 1865 for his scientific work, because the club considered this status to have lapsed on Agassiz's death. In 2020, the Stanford Department of Psychology requested to remove a statue of Louis Agassiz from the front façade of its building.
Louis Agassiz