Consider a man alone. What may he do?
Wrong question, of course. He is alone; there are no others to restrain him. His privileges precisely match Jefferson’s assertion. He has life, he has liberty — that is, he may do anything he can do — and he can direct his activities in any way that might please him. He can speak as he wishes, although that doesn’t have much utility in his situation; he can worship whatever god(s) he may recognize as extant. He is totally at liberty; his activities and behavior are restricted only by his own abilities and the resources available to him.
Can the man alone eat? Certainly he may — or, rather, the question of permission is irrelevant. If his abilities suffice to acquire food, there is no-one to prevent him from eating. On the other hand, there is no force or circumstance that will deliver food to him absent his own effort. Certainly it requires effort on his part (however trivial) to speak, but this is effort expended to perform the action; equally, effort is required for him to bite, chew, and swallow. In order to eat, he must perform the precursor effort of acquiring food. He has the natural right to speak, but not the natural right to eat — although he does have the natural right to perform the precursor effort of seeking food.
Can the man alone own? Well, certainly he can possess in the same sense he can eat. If he picks up a stone — that is, makes the precursor effort of acquiring — it is his so long as he maintains control over it. He has the natural right to acquire, but possession requires that precursor effort.
The example is oversimplified, in the same way the examples found in a first course in physics are oversimplified. Physics 101, sometimes called “statics and mechanics”, makes much use of idealized concepts — objects with mass but zero dimensions, surfaces entirely lacking friction, strings of infinite strength and flexibility but having no size other than length, and the like. Such idealizations are not found in the real world, but they serve to introduce the student to fundamental concepts. In the same way, the idealization of the “man alone” serves to illuminate the basics, but Universe applies myriad complexities that must be accounted for before applying those fundamentals to real life.
If the man alone puts the stone he possesses down and walks away, it is no longer in his possession; he no longer controls it. The forces and animals surrounding the man alone, here considered impersonal and lacking will, may affect the stone in myriad ways when the man no longer has it in his possession.
This exposes an important distinction: ownership is maintaining existential control over something when the owner is no longer present, and that requires introducing another force of will, that is, another person. The stone might still be affected by impersonal forces, swallowed up by an earthquake or shat upon by a bear; but if the second person recognizes the first’s ownership of the stone, she will not pick it up and put it to use because it is owned by the first.
In general, the natural rights of the man alone may or may not be expressible in action when he is no longer alone, but they remain as natural rights in the same way torque, mass, rigidity, and other fundamentals of introductory physics remain when real-world complexities are added.
When the person is no longer alone, but embedded in a society with other persons, the question of natural right may be illuminated by prevention, deterrence, and the distinction between the two. The basic or Jeffersonian natural rights can be neither prevented nor deterred. The person has life, and continues to have that natural right until the right is violated by killing him. Other natural rights can be deterred, but not prevented — speech, for instance, can be deterred by promising punishment a posteriori, but no a priori force can prevent it. On the other hand, possession can be both deterred (by promising punishment a posteriori) and prevented (by a priori deterring the precursor action of acquisition).
The natural rights of life and speech can be violated by taking or punishment, but their expression cannot be prevented. Contrived rights such as possession can be prevented. Subtleties and nuances abound, and may obscure the issue in any given case, but resolution is possible by applying the simplifying assumption of the man alone and making the distinction between deterrence and prevention when he is no longer alone.
Some may consider that I am attempting to justify the Left’s assumption that ownership is evil and must be eliminated. Quite the contrary; it is my assertion, supported I believe by both theory and practice, that ownership and the concept of “property” are vital to a complex society’s success. However, arguing that property is a natural right is a non-starter, and discredits the very concept of natural right — and the Left takes full advantage. If the Right’s arguments are to carry the day, the distinction must be acknowledged.