There are three standard attitudes of religions towards one another: exclusive, inclusive, or pluralist. The exclusivist states their religion and only their religion is true and offers a path to salvation, or in the Buddhist sense, the end of suffering. The inclusivist privileges their own religion, while recognizing and valuing similar traits of other religions and, in some cases, even recognizing their stereological efficacy. The pluralist places all religions on equal footing, equally capable of salvation, and equally valid as life choices. However, each of these attitudes is problematic.
Buddhism cannot be exclusive because it makes no claims to ontological truth. Indeed it can make no claims to ontological truth given the nature of sunyata, or emptiness. In fact, no religion, philosophy, or any claim whatsoever can be said to be ontologically true due to the inability of language to exactly describe existence. (I reserve judgment on the realm of mathematics and, by extension, physics, but only by assuming an “evil genius” or “Matrix” like situation does not pertain.) Buddhism, as compared to other religions, merely emphasizes this recognition.
Buddhism is and has been broadly characterized as inclusive. Historically, Buddhism adapted to and, in some cases, even merged with indigenous Asian religions in countries to which it spread. In many cases, Buddhists practicing in one country might not even recognize the practices of another country as Buddhism upon cursory examination.
Here in the West, it is continuing to adapt. Recent scholars have even asserted it is not a religion at all, but rather a philosophy, perhaps in part due to the lack of ontological truth claims discussed above. As a philosophy, they hold, it is entirely accommodating of all world religions. Any religion can include Buddhist ideas or be included within Buddhist practice either in whole or in part.
However, I believe these claims to be misleading, altering the face of Buddhism to suit one’s personal preferences (i.e. anti-religious bias), superficial (i.e. misunderstanding the Dharma), or simply wrong (i.e. causation being antithetical to a supra-causational divinity). In addition, inclusive attitudes run the risk of damaging both Buddhism and other religions by removing the “agreeable” aspects from their larger framework and reinterpreting them in a new and, perhaps, wildly incorrect manner.
Yet at the same time, Buddhism cannot be entirely pluralist. The Buddha stressed that different practices and teachings are more suited for certain individuals at certain times (he even discouraged conversion from one's native theology to Buddhism), but this should not be interpreted as relativism. To say Christianity or Hinduism is just as good as Buddhism is to devalue not only Buddhism, but the other religions as well. It entirely ignores the merits of each religion in question and closes off opportunities to exercise discriminating awareness. If any path is just as good as any other, then no path is just as good as any path, so we might as well sit on the couch all day eating potato chips and watching soap operas. In addition, Buddhism has been characterized as a stereological phenomenology, that is, concerned with the effects and efficacy of various practices leading towards the end of suffering, not their underlying claims of truth. Therefore, a Buddhist cannot help but evaluate other religions by their effects and efficacy, which neither over the long course of history nor between modern-day individuals can be described as equal.
In some ways, Buddhism must be a little bit pluralist, a little bit inclusive, and, yes, even a little bit exclusive. In so doing, however, it is really none of the three, but rather an as-of-yet unnamed fourth position. Of course, this a really brief and very dirty characterization of the three recognized positions and the trouble of each. A Buddhist view of other religions may, in the end, fall so close to one of the three as to be practically indistinguishable. Yet, my intuition tells me there is a fourth way.
We could call it the Middle-of-the-Triangle Way, but that’s a bit of a mouthful.