All the evidence leads us to conclude that they are not, as is explained here. They have no nervous systems or other structures that could perform similar functions in the bodies of sentient beings. Due to this, they can’t have experiences, so they can’t feel pain. This backs what we can observe, as plants are not beings with behaviors like conscious beings. In addition, we can consider the function that sentience has. Sentience appeared and has been selected for in natural history as a tool to motivate actions. Due to this, it would be totally pointless for plants to be sentient, since they can’t run away from threats or make other complex movements.
Some people talk about “plant intelligence” and plants’ “reaction to stimuli”, but this just refers to some capacities they have that don’t entail any form of sentience, feelings or thought at all.
Despite what some people say, claims to the contrary have no scientific grounding. It is sometimes argued that according to some scientific findings plants have been shown to be conscious, but this is just a myth. No scientific publication has actually backed this claim.
Animals are harmed and killed in farms and slaughterhouses because of the demand for animal products. By buying animal products we contribute to the demand of these products, due to which more animals will be exploited in the future. By going vegan we don’t save those animals who have already been killed, but we stop other new animals from suffering that fate.
We value our lives and usually consider killing someone a terrible harm to that person. This is because when we die we lose all the positive things that we could otherwise experience in the future. For this same reason, dying is not bad only for humans, but for all beings whose lives can include positive things. This includes all sentient animals who can experience pain and pleasure. This is something that anyone who has lived with an animal like a dog can understand: when they die, we can see it would be better for them to remain alive.
Due to this, even if it were possible to kill animals without causing them any pain, by killing them we would still be harming them. We would still be depriving them of the opportunity to have future positive experiences.
In addition, it’s important to bear in mind that it is impossible to feed millions of people with animal products without exploiting animals terribly. It would not be feasible to raise the billions of animals needed every year to meet this demand in comfortable conditions.
The same is true of the way they are killed. Consider, for instance, what happens at slaughterhouses, where many animals are unintentionally boiled or skinned alive (setting aside cases of intentional cruelty to them). This happens because otherwise slaughterhouse workers would have to go at a much slower pace. The demand for animal products, however, requires that millions of them are killed every minute.
Moreover, the overwhelming majority of animals killed for human consumption are aquatic animals such as fishes, and it is virtually impossible to kill them painlessly when they are fished.
We aren’t forced to eat animals by our biology. We can eat animal products, but we can also eat other things. Both things are compatible with our biological nature. More to the point, whether something is natural or not does not necessarily mean it is good or right to do. Many natural things such as hurricanes, malaria, and ebola are very harmful. Also, there are many attitudes humans have held for a long time that are clearly objectionable, including violent attitudes towards others. It may be argued that such attitudes are natural. The interesting point here is that in order to oppose them we don’t need to reject the claim that they are natural. They may be natural, but accepting this doesn’t imply granting in any way that there’s anything positive in them.
Our ancestors didn’t have houses, books, or health care as we have, and that doesn’t mean we have to reject those things in order to live more naturally. Rather, our decisions can be made on the basis of what is better or worse. In the case of what we eat, what is important is who may be harmed by our decisions.
Some people would claim it is justified to kill someone who attacks you, while others would deny it. But no one can reasonably claim that this makes it acceptable to kill other people in general. The same applies to other animals. All this is setting aside, of course, the simple fact that the animals we exploit are not attacking us. (Rather, we are the ones attacking them.)
Some people may reply “Yes” to this claim, while others may say “No”. But we’re not on desert islands without any plant food. Rather, we can decide what to eat. So this question is not relevant to deciding whether to become vegan. What matters is that we can avoid harming others, and have the power to do so.
The number of domesticated animals would decrease very significantly if the world went vegan because animals would no longer be forcibly reproduced by the animal industry. There would no longer be billions of animals coming into existence, suffering terribly, and then being killed by us when they are still very young.
If the demand for animal products decreases and more people become vegan, there are new jobs that will be created, though jobs in the animal exploitation industries will be lost. We must note, however, that animals exploited for human use suffer terrible harms that are more significant than the harm of losing a job. Being unemployed is undesirable, but it is usually reversible, while being killed is not only undesirable but also represents an irreversible harm to sentient beings. Most of us would prefer to lose a job than to lose our lives.