8 conditions for a sammasambuddha

Eight conditions for a samma-sam-buddha, according to Khuddaka Nikaya, Buddhavamsa 2.59:
#Manussatta: the human state. The resolve to become a Sammāsambuddha can be made only during a life in which one is a human being.
#Liṅgasampatti: possession of the right sex. One must be a man, not a woman, a congenital eunuch, or a hermaphrodite.
#Hetu: cause. Possessing the supporting conditions for attaining arahantship in that same life, if he were to exert himself towards this end.
#Satthāradassana: the sight of the Teacher. This means an encounter with a Sammāsambuddha, as when Sumedha met the Buddha Dīpaṅkara and declared his resolve in his presence.
#Pabbajjā: going forth into the homeless life. One must have left the household life and be an ascetic who holds to the doctrine of the efficacy of kamma, like the ascetic Sumedha when he made his resolve.
#Guṇasampatti: attainment of special qualities. One must have attained special or distinctive qualities, beginning with the jhānas, like Sumedha, who had attained the five mundane higher knowledges (abhiññā) and the eight attainments (samāpatti) when he made his resolve before the Buddha Dīpaṅkara.
#Adhikāra: extreme dedication. At the time of making one's resolve to become a Sammāsambuddha one must be prepared to sacrifice everything, even one's life.
#Chandatā: strong desire. Having a strong desire to become a Sammāsambuddha, no matter how great the difficulties and obstacles one may encounter. For example, if he were told that to attain sammāsambodhi it would be necessary to tread his way across an entire world-system filled with flameless hot coals, or tread his way across an entire world-system whose ground was bespread with spears and sharp-pointed bamboo sticks, or wade across an entire world-system filled with water, or cut his way through an entire world-system choked with thorny bamboo plants, — he would reply: "I can do that."
==An alternative, Modern Theravada reading of the 8 conditions==
Virtually no one claims that women cannot attain enlightenment in Buddhism. The Buddha was very clear that women are able to attain to the final state, the goal of Buddhism; enlightenment and Nibbana. The Buddha was asked in so many words, "is there even one woman nun who is fully enlightened?" The Buddha responded, "There are not only one hundred . . . or five hundred, but far more bhikkhunis, my disciples, who by realizing for themselves with direct knowledge here and now enter upon and abide in the deliverance of mind and deliverance by wisdom . . ." Sutta 73 Majjhima Nikaya and also in other suttas too. 
There are three types of buddhas or enlightened ones. One is an Arahant who teaches others; another is a silent buddha who attains enlightenment but does not teach, but presumably can still send his or her “rays” of metta - loving kindness to the world. The third type of buddha is a samma-sam-buddha, which is a special buddha which comes around only once every 5,000 to 15,000 years or even longer (sometimes one billion years or more while a world system is re-evolving) to teach the Dhamma when the Dhamma has died out from the world. This “savior” type of buddha is who the historical Buddha was. 
In all three types of buddha, there is full liberation and Nibbana. One does not need to be a samma-sam-buddha to attain enlightenment or Nibbana. Thus, full liberation is open to women. However, there are fundamentalist Buddhists who contend that only a man can become a samma-sam-buddha. The issue is mostly meaningless, since we already have a Buddha for our time and well over 99% of us will not attain to any of the three types of buddha, let alone the samma-sam-buddha title. But it still makes a point that only men can have this title and this is still a subtle form of sexism which can be used to discriminate in other ways. 
The famous Theravada teacher Dipa Ma, was sitting quietly in her room one day while her teacher and another teacher were talking. Her teacher remarked that only a man can become a buddha (samma-sam-buddha). Dipa Ma immediately rose from her silence and exclaimed, “I can do anything a man can do!” The guests erupted with laughter and agreement. Dipa Ma was an amazing woman who mastered all the Jhanas and taught Vipassana from her humble small home in India. 
What is the origin of this idea that only a man can become a samma-sam-buddha? There is the list shown above of who can be a teaching samma-sam-buddha (Khuddaka Nikaya, Buddhavamsa 2.59) and one of the items includes being a male. The Buddhavamsa was one of the most recent, youngest books of the Pali Canon. It is one of the furthest books in years after the time of Buddha. (See: Chronology of Pali Canon) It could be from the 32 marks of a great man. There are a few suttas which mention the 32 marks of a great man and how the Buddha possesses these marks. If you see the list of these so-called great marks, you will see that they are truly mythological and completely legendary; certainly nothing to be taken seriously or to justify sexism. 
Some of the items on this list of 32 marks of a great man include a lion's chest, a jaw like a lion, a tongue that is so long that it can reach the forehead and both ear holes, 40 teeth, and a penis encased in a sheath. Because the list is that of a great “man” and includes the penis encased in a sheath, it obviously excludes women. But anyone with a little common sense can see these mythological claims are designed to elevate the status of religious leaders by making them sound super human. It helps to convert the uneducated masses, but does nothing to shed more light on the wonderful teachings of the man who became a buddha. 
The origin of the 32 marks of a great man has nothing to do with Buddhism. This is a pre-Buddhistic concept. This is proven by the fact that Asita, the seer who came to see the baby Buddha just after birth predicted that the Buddha will either become a great king and ruler or a great religious man. This seer named Asita, checked the baby Buddha and found the 32 marks of a great man present on Buddha. This was before the Buddha's enlightenment, before Buddhism, and before the Buddha's first teachings.(Sutta Nipata 3.11)
This situation is not limited to the Theravada and in fact Zen and Vajrayana have an even more patriarchal line with all of the Zen leaders of the past being male and the re-births of all Dalai Lamas have been male as the search committee only looks for recently born boys after the passing of a previous Dalai Lama.
Another possibility is that only a male can be a samma-sam-buddha because in a male-dominated society, a female will not be accepted as a savior type of teacher and then the teachings will not be renewed and followed. In a further feminist perspective, a samma-sam-buddha only comes when males are dominating the world for too long, because then the Dhamma will die-out.
Enlightenment does not require one to be a samma-sam-buddha. Attainment of enlightenment and Nibbana is achieved by the many thousands of Arahants too. Even if we accept that a samma-sam-buddha must be male, it is a moot issue when we consider that 99.99999999999999999999% of all people alive right now will never be a samma-sam-buddha. This is because a samma-sam-buddha only comes when the Dhamma has died out and the Dhamma is re-discovered by the enlightenment of the samma-sam-buddha. And we can also add to this fact, that it is just as likely that some future samma-sam-buddha who is alive today might be a female rather than male, in their current life.
==See also==
*Buddhism and Misogyny
*28 Buddhas
==References==
*The Complete Book of Buddha's Lists -- Explained. David N. Snyder, Ph.D., 2006.
*http://www.TheravadaBuddhism.org/
*http://www.TheDhamma.com/
Category:Buddha's Lists