Most of the recent theoretical writing, justifying intellectual property rights consists of struggles among and within four approaches. These theories are commonly referred as labor, utilitarian, personality and social planning theory. The labor theory that currently dominate the theoretical literature springs from the propositions that a person who labors upon resources that are either unowned or â€œheld in commonâ€ has a natural property right to the fruits of his efforts and that the state has a duty to respect and enforce that natural right. These ideas, originating in the writings of John Locke, are widely thought to be especially applicable to the field of intellectual property, where the pertinent raw materials (facts and concepts) do seem in some sense to be â€œheld in commonâ€ and where labor seems to contribute so importantly to the value of finished products.
The intuition is that the person who clears unowned land, cultivates crops, builds a house, or creates a new invention obtains property rights by engaging in these activities. The labor justification is mostly held in Europe and is included in the Berne Convention. In France it is specifically encoded in the so called 'droits moraux', or moral rights, that French authors have in addition to economic rights. The moral rights involve things such as the right to decide whether something is to be published, the right to withdraw it from the market, and the right of attribution. They cannot be sold by the author, and are perpetual. The interests that the labor justification centers on mostly are those of authors and publishers. This theory grounded on two basic propositions. According to the first proposition, the preservation of mankind is a fundamental law ofnature; it is Godâ€™s will. From this, it is infers that man has a natural obligation to ensure his preservation
. This implies that man has a natural right to his preservation and to the means necessary for his preservation (e.g., meat and drink).
The second proposition is that God gave the earth â€œto mankind in common.â€
However, for man to enjoy the fruits of the earth, for those fruits to be at all beneficial to any particular man, there must to be a wayto appropriatethese fruits so that others can no longer claim them.
Locke the devotee of this philosophy, asserts that everyone has a property right over his own person and hence also over the labor of his body and the work of his hands.
This brings him to his famous explanation of the origin of property rights: the appropriation of a thing occurs by man applying his laborto it, by mixingthe thing with his labor. By means of his labor he adds something of his own to the thing and this way he excludes others from having a right to it. For such acquisition of property, the consent of the other â€œcommonersâ€ is not required, Locke maintains.
Appropriation can never amount to robbery of others because everyone has the right to â€œhis shareâ€ and no more than that. â€œHis shareâ€ corresponds with what he can use. The consent of others could only be required if the rights or liberties of others are being violated and this cannot be the case if no one appropriates more than â€œhis share.â€
However, Locke specifies two provisos that must be met in order for the appropriation to be justifiable. The first condition is the â€œenough and as goodâ€ condition: there must be â€œenough, and as good left in common for others.â€
Thus, things may only be appropriated if, afterwards, a sufficient number of the same or similar things remain (similar also in terms ofquality the remainder must be just as good). The second condition is the â€˜non-wasteâ€™ condition. Man is not allowed to appropriate more than he can use (even if he made the things in question himself).
Alternative interpretation of Locke's labor justification can be called the "labor-desert" or "value-added" theory. This position "holds that when labor produces something of value to others, something beyond what morality requires the laborer to produce then the laborer deserves some benefit for it."
This understanding of property does not require an analysis of the idea of labor. Labor is not necessarily a process that produces value to others. It is counterintuitive to say labor exists only when others value the thing produced. It also would be counter to Locke's example of the individual laboring and appropriating goods for himself alone.
The "labor-desert" theory asserts that labor often creates social value, and it is this production of social value that "deserves" reward, not the labor that produced it. On the other hand the problem with labor theory is: if one accepts that mixing labor with something occasions the coming into existence of a property right, the question remains as to the boundaries of that property right. How can one decide what exactly has become the property of the person who performed the labor? This question can also be put in terms ofthe valueof the result. A distinction should be made between the value attributed to the object of the labor and the value attributed to the labor itself (in other words, the addedvalue). Determining the proportionality of each of these values in respect of the total value of the object to which labor has been applied would seem to be very difficult.This weakens the justificatory strength of the labor theory of property. Another problem is that â€˜intellectual objectsâ€™ usually stem from ideas of predecessors. The labor of these predecessors also forms a component in the total value of the final result a component whose valuevaries case by case. This has important implications for the question who is entitled to the value of the final result. As Edwin Hettinger explains: A person who relies on human intellectual history and makes a small modification to produce something of great value should no more receive what the market will bear than should the last person needed to lift a car receive full credit for lifting it. If laboring gives the laborer the right to receive the market value of the resulting product, this market value should be shared by all those whose ideas contributed to the origin of the product. The fact that most of these contributors are no longer present to receive their fair share is not a reason to give the entire market value to the last contributor.
The question also arises as to whether Lockeâ€™s two provisos apply in the context of intellectual, abstract, intangible objects (as opposed to tangible objects). As for the second proviso, man may only appropriate as much property as he can use, the question arises, e.g., whether waste can occur in the case of ideas. It seems unlikely that an idea as such could be â€˜wasted,â€™ but the possibilities offered by an idea can be. If someone acquires an intellectual property right on an idea and does nothing with it, the â€˜non-wasteâ€™ provision would seem to be violated. If something is left unused by the appropriator, while others need it, the waste is all the greater. For example, taking into consideration the patent system (intellectual property right). One aspect of this system that can certainly induce waste is that, in its present form, it does not oblige patent holders to â€˜workâ€™ (exploit) their invention. The history of the patent system shows that this has not always been the case in industrialized countries, and in most developing countries, a â€˜working requirementâ€™ for patented inventions has existed until recently (or continues to exist).Even if a patent is exploited, waste can occur. For the result of granting a patent is that the patentee can put restrictions on the use of the invention. Since a characteristic feature of the objects of intellectual property rights is their so-called â€˜non-exclusiveâ€™ nature (the fact that they can be used by many people simultaneously), limiting their use artificially can indeed amount to waste. The extent of the waste would seem to depend on the extent to which others need the invention in question. In short, one can justify propertizing ideas under Locke's approach with three propositions: first, that the production of ideas requires a person's labor; second, that these ideas are appropriated from a "common" which is not significantly devalued by the idea's removal; and third, that ideas can be made property without breaching the non-waste condition. Many people implicitly accept these propositions. Indeed, the Lockean explanation of intellectual property has immediate, intuitive appeal: it seems as though people do work to produce ideas and that the value of these ideas especially since there is no physical component depends solely upon the individual's mental â€œwork." Bibliography.
Becker, The Moral Basis of Property Rights Hughes J, The Philosophy of Intellectual Property (Georgetown Law Journal 1988) Guardian. Available [Online] at: http://www.law.harvard.edu/faculty/tfisher/iptheory.html#_ftn5
[Accessed: 1/11/2014]. Hettinger C, Justifying Intellectual Property Locke, II, V, 25, 26, 27, 28, 31,36,37,38, 46
, Justin Hughes, "The Philosophy of Intellectual Property," Georgetown Law Journal, 77 (1988): 287, at 299-330 
Locke, II, V, 25. 
Locke, II, V, 26 
Locke, II, V, 27 
Locke, II, V, 28. 
Locke, II, V, 36 and II, V, 46 
Locke, II, V, 27 
Locke, II, V, 31. See also Locke, II, V, 37 and II, V, 38 
Becker, The Moral Basis of Property Rights, IN PROPERTY, NOMOS XXII, supra note 4, at 187, 193. 
Erwin C. Hettinger, â€œJustifying Intellectual Property,â€ Philosophy & Public Affairs 18 (1989)1: 38.