primary vs secondary qualities

Primary Qualities are those qualities that are not dependent on the relationship between the perceiving subject and the object being perceived, but rather exist in the object itself. Examples include mass, size, shape, and texture.
This category includes accidents, which are qualities that are not essential to the object but may still be present in it.

Secondary Qualities are those qualities that are dependent on the relationship between the perceiving subject and the object being perceived, and do not necessarily exist in the object itself.
Examples include colors, smells, tastes, and tactile sensations.


A secondary quality is a quality that exists in the perceiver's mind and is not a property of the thing in itself.
A primary quality is a property of a thing in itself, independent of the perceiver.
If something has a secondary quality, it must be perceived by a perceiver.
If something is perceived by a perceiver, it must have some primary quality that is perceived.
Therefore, if something has a secondary quality, it must also have a primary quality.
Therefore, it is impossible for something to have secondary qualities but no primary qualities.




This statement  “Any entity qualified by a necessary attribute concomitant to it can only exist along with its necessary attribute”. If it helps at all, the statement can also be transliterated in Arabic as “al-mawsuf bi-sifa lazima lahu la yakunu mawjudan bi-dun sifatihi al-lazima lahu”. Explain what the statement means:


The statement means that any entity that is qualified by a necessary attribute (a characteristic or property that is essential to its nature or identity) cannot exist without that attribute. In other words, the necessary attribute is concomitant (accompanying, occurring with or as a result of) the entity and is an integral part of its existence. This aligns with the concept in ST that necessary attributes are essential to the nature or identity of an entity, and that an entity cannot exist without them.





Demonstrate the Primary Qualities of an entity are not other than it but the distinctions of those Primary Qualities as "other" are Secondary Qualities:


An entity can have certain attributes that are necessary for it to exist. These included in what are known as Primary Qualities.
The distinctions of those Primary Qualities, or the way that they appear to us, are called Secondary Qualities.
For example, a chair has the Primary Qualities of being a physical object with a certain shape and structure that allows it to support the weight of a person. The color of the chair, or the way that it appears to our senses, is a Secondary Qualities.
The Primary Qualities of an entity are not other than the entity itself, but the secondary attributes are the ways that those Primary Qualities are distinguished from one another or perceived by us.
Therefore, it can be concluded that the Primary Qualities of an entity are not other than the entity itself, but the Secondary Qualities are the distinctions of those Primary Qualities as "other."