123
oping. An individual property p is an instance of a general property P, and can be
identified as the property P[a] of an object a or as the value p of property P.
Second, the complementarity of the two modes of identification of individual
properties is exploited in measurement. The information conveyed by a Basic
Evaluation Equation
property of an object value of a property
=
is indeed that an individual property p 1 , identified as a property of an object (i.e.,
p 1 = P[a] for a given object a), and an individual property p 2 , identified as a value of
a property (i.e., p 2 = p for some value p of P), are reported to be the same individual
property, p 1 = p 2 and therefore P[a] = p, as the result of the evaluation. Any Basic
Evaluation Equation is then interpreted to be a mere identity from an ontic point of
view, but a significant relation from an epistemic point of view.
15
This reveals the
fundamental meaning of the Basic Evaluation Equation:
• The property P[a] of the object a is an individual property p (the mass of any
given object is a given mass).
• By means of a measurement the individual property p that was known as P[a] is
identified also as a given value p of P (the mass that was known as the mass of a
given object is identified also as 1.2345 kg).
These two basic arguments need to be carefully presented, explained, and justified,
and to this purpose the balance of this chapter and the next one are devoted.
5.2 Some clarifications about properties
The concept has some ambiguities that we need to discuss before proceeding with our analysis.
5.2.1 Properties of objects as entities of the world
First of all, by considering properties of objects as associated with modes of interaction of the objects with their environments we acknowledge that properties of
objects exist in the empirical world, and thus not only in our minds.
16
A given object
15 This double meaning—an ontic identity that is a significant epistemic relation—is more extensively discussed in Sects. 5.3.2 and 6.4.
16 The concept is so general that this condition needs to be specified. For example, one
could consider that number 2 has the property of being even and of having 4 as its square: considering these as modes of interaction would be peculiar, at least because the very idea that numbers
interact with something empirical is peculiar in turn. Hence our analysis actually relates to empiri5.2 Some clarifications about properties
oping. An individual property p is an instance of a general property P, and can be
identified as the property P[a] of an object a or as the value p of property P.
Second, the complementarity of the two modes of identification of individual
properties is exploited in measurement. The information conveyed by a Basic
Evaluation Equation
property of an object value of a property
=
is indeed that an individual property p 1 , identified as a property of an object (i.e.,
p 1 = P[a] for a given object a), and an individual property p 2 , identified as a value of
a property (i.e., p 2 = p for some value p of P), are reported to be the same individual
property, p 1 = p 2 and therefore P[a] = p, as the result of the evaluation. Any Basic
Evaluation Equation is then interpreted to be a mere identity from an ontic point of
view, but a significant relation from an epistemic point of view.
15
This reveals the
fundamental meaning of the Basic Evaluation Equation:
• The property P[a] of the object a is an individual property p (the mass of any
given object is a given mass).
• By means of a measurement the individual property p that was known as P[a] is
identified also as a given value p of P (the mass that was known as the mass of a
given object is identified also as 1.2345 kg).
These two basic arguments need to be carefully presented, explained, and justified,
and to this purpose the balance of this chapter and the next one are devoted.
5.2 Some clarifications about properties
The concept
5.2.1 Properties of objects as entities of the world
First of all, by considering properties of objects as associated with modes of interaction of the objects with their environments we acknowledge that properties of
objects exist in the empirical world, and thus not only in our minds.
16
A given object
15 This double meaning—an ontic identity that is a significant epistemic relation—is more extensively discussed in Sects. 5.3.2 and 6.4.
16 The concept
could consider that number 2 has the property of being even and of having 4 as its square: considering these as modes of interaction would be peculiar, at least because the very idea that numbers
interact with something empirical is peculiar in turn. Hence our analysis actually relates to empiri5.2 Some clarifications about properties