Plant ethics

A commonly used argument among anti-vegans is that plants should be given moral consideration.

Basic knowledge in the field of neuroscience and/or evolutionary biology will make it quickly apparent that plants' sentience is pseudoscience. There is empirical and indisputable evidence that plants are not sentient--they lack the structure that would allow for sentience (no central nervous system to process and interpret information subjectively). Scientific consensus is that plants aren't sentient. [1]

"We begin by stating simply that there is no evidence for structures such as neurons, synapses or a brain in plants."

Plant sentience is a completely bogus concept that's unfounded, basing itself on no evidence and going against evidence. The central nervous system and the parts of a neural network required to allow sentience to exist aren't unclear, and are well understood. Certain small insects (such as flees) are in a grey area and may already be non-sentient, let alone plants. Plants' sentience is a belief that can only exist if there is ignorance (or willful ignorance) of basic neuroscience/evolutionary biology, as it's not only disproven by looking at the science, but is simply absurd.

Consciousness and intelligence

People trying to make a case for plant ethics tend to often use 'consciousness' as the main reason why plants should have inherent moral value.

Consciousness is a very vague term, often used interchangeably with sentience, but still being a vague concept that leaves room for interpretation. What is X supposed to be conscious of?
They usually rely on consciousness for two reasons:

• lack of knowledge of a well defined word expressing awareness and subjectivity (e.g. sentience), or
• as a way to cover their bases--dishonestly being intentionally vague, so that they can't easily be proven wrong. If a good argument is used against them they have wiggle room to change the meaning of consciousness. This is usually done by including other vague terms like intelligence into it (i.e. plants have consciousness, because they have intelligence, just like other beings that have consciousness).

There is no clear agreed-upon definition of consciousness. Possible definitions range from wakefulness, to selfhood, to mental state, to mental processes, to sentience, to having a soul and other spiritual meanings.

This is why it's important to establish the meaning of the language used before delving into a discussion, and why using the term sentience is a much better way to convey the concept of awareness/feelings/wants/subjective experience.

Because of the vagueness of the term consciousness, people often use that as reason as to why consciousness would be not well understood, and that therefore it wouldn't known who/what it applies to. Which leads to the conclusion that the line where beings/things to whom qualities such as awareness, feelings, wants, and the ability to have subjective experiences apply to, is either up to interpretation or is simply not known by science.
This is why it's important to not use sentience interchangeably with consciousness, as one is well-defined term, while the other is vague and easily interpreted differently.

If:
1. Sentience = consciousness
2. Consciousness is vague and undefined/unknown
Then:
3. Sentience is vague and undefined/unknown

The term 'intelligence' is used in a similar fashion, smearing the meaning of sentience with vagueness and uncertainty.

Intelligence is defined by Wikipedia as

"Intelligence has been defined in many ways: the capacity for logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can be described as the ability to perceive or infer information, and to retain it as knowledge to be applied towards adaptive behaviors within an environment or context."

It's apparent how such a loose definition can be applied to anything that can perform a task.
Computers have intelligence, skin has intelligence, plants have intelligence, even a calculator has intelligence. Intelligence can refer to many different things, and it isn't remotely interchangeable with sentience, or with any of the concepts held by sentience.

An argument often used for plant ethics is that plants have intelligence to do different tasks. But that doesn't indicate sentience, as there are plenty of example of other things doing the same tasks, even in a significantly more complex way, that aren't sentient. What plants do is a survival strategy, and can be classified as intelligence--but intelligence isn't sentience (more explained below).

Commonly used arguments for plants' sentience

Plants' intelligence

Plants having intelligence leading to plants having sentience is a non-sequitur fallacy. https://www.logicallyfallacious.com/logicalfallacies/Non-Sequitur
As explained, intelligence doesn't mean sentience, and below are some examples where intelligence is there without sentience, showing that intelligence isn't dependent of sentience.

- Plants have the intelligence to gather information about their surroundings, and act accordingly (i.e. grow towards the sun). They're therefore sentient.

Gathering data and using it isn't inclusive of sentience, it's a task performed by many things.
Gathering environmental data is necessary for many non-sentient organisms' survival, and a task performed by many non-sentient things. Bacteria can sense the density of cells, and regulate gene expression accordingly (quorum sensing). Self-driving cars are able to gather information about their surroundings, and act accordingly. But they aren't sentient.

- Plants have the intelligence to communicate (i.e. sending signals to other plants for incoming threats). They're therefore sentient.

Communication is found in many places, from basic electrical wiring, to Alexa, to various types of cellular communication.
Many software programs communicate, sending notices and alerts for various stuff (such as apps telling us X is happening). Communication is intelligence, but doesn't mean sentience.

- Plants have the intelligence to detect danger, and release chemicals as protection (i.e. an insect trying to bite the plant, and the plant releasing chemicals that would bother and deter the insect). They're therefore sentient.

Defensive systems are a survival strategy found in every single organism, and in software programs too.
Anti-virus programs are a good example of something that can detect threats efficiently, and even take it to a step further, going as far as eliminating them. Other systems that have the intelligence to detect threats/unwanted stuff are spam filters, smoke alarms, medical equipment, and speedometers. Detecting dangers or unwanted stuff isn't a sign of sentience.

Plants react to stimuli

The plants' reaction to stimuli may be the most commonly used argument for plant ethics.
Reaction to stimuli is unrelated to sentience. Such a thing can be seen with every organism and many appliances/software programs--and even basic chemicals.
Examples of reaction to stimuli include: a computer reacting to you pressing the on/off button, a blender reacting to you undoing the lid and it halting as a safety mechanism, baking soda reacting with vinegar, muscles reacting to cold by tensing up, and a search engine like Google reacting by writing something in the text field and pressing enter.
The term 'reaction' is applicable to pretty much anything happening, as there is an action-reaction mechanism--i.e. I pour the vinegar on the baking soda and the acid of the vinegar goes in contact with the baking soda (action, stimuli), and there's an immediate chemical reaction (reaction).

Plants move

Some people believe that because plants move (i.e. sunflowers changing direction to face the sun), then they'd have 'consciousness' (sentience).
While fast and immediate movement is an indicator for a need of sentience in evolutionary biology (i.e. seeing and interpreting threats immediately, and running away), simply showing movement isn't proof of sentience.

Many organisms and artificial inventions move without external input, and aren't sentient. Examples range from a self-driving car moving on its own, to NPCs in a game walking around and fighting (even showing complex behavior), to a printer moving mechanical parts for the printing process.

Some scientists say plants are sentient

Some plant ethics advocates use the fact that some professors and scientists are talking about plants' intelligence as a reason for believing that plants are sentient.

The majority of those professors simply show certain tasks that plants are able to do (addressed above), and talk about how plants behave--and do not believe plants are sentient creatures. The others that do, do not have any amount of evidence to show in support of their belief. There needs to be a strong lack of understanding of neuroscience and evolutionary biology to hold the belief that something lacking a central nervous system is sentient.

This argument is a clear example of the appeal to authority fallacy.https://www.logicallyfallacious.com/logicalfallacies/Appeal-to-Authority
'Insisting that a claim is true simply because a valid authority or expert on the issue said it was true, without any other supporting evidence offered.'

Intelligence doesn't mean sentience (as shown above). Intelligence is an ambiguous term referring to many possible different things, and can be applied to anything that is able to do a task.

The few professors arguing for plants to be sentient do not show any proof for their belief, and leave it unfounded, using non-sequiturs that would somehow prove the plants' sentience (i.e. plants communicate, therefore they're sentient).

There are also professors/scientists believing in astrology, the flat Earth theory, and many more pseudoscientific absurd beliefs.
The common trait among them, is that they do not provide any evidence for their theories, and instead rely on non-sequiturs.

Examples:

• the Earth isn't visibly round -> the Earth is flat
• plants react to stimuli and release chemicals as a survival strategy -> plants are sentient
• X person felt better while X person happened to be wearing crystals -> crystals have healing properties
• plants have a system to signal threats to other plants, so defensive chemicals to deter insects are released as a survival strategy -> plants are sentient
• prayer sometimes makes people feel better -> player healing is effective in treating diseases

Veganism kills more plants

Some carnists, after having tried to prove plants are sentient and worth moral consideration, then use the argument that because veganism kills plants, veganism isn't moral either.

1. Plants are simply not sentient, so the argument has a false premise. They hold no inherent moral value.

2. If plants were to be sentient (to entertain the hypothetical), then veganism would be even more the morally right thing to do, and eating animal products would be even worse, because:

• animals are fed plants, and because of thermodynamics a lot more plants are used to feed and grow animals than what they would be used to feed humans (e.g. a lot more plants are used in the process of feeding animals that then are fed to us, than if we just ate the plants directly)
• animal products are the biggest cause of deforestation, having to make space and paving over forests for animal feed and pastures, therefore killing a lot of plants in the process